diff --git a/include/GenericHashEntry.h b/include/GenericHashEntry.h
index b41e3bca81..7f3c05eade 100644
--- a/include/GenericHashEntry.h
+++ b/include/GenericHashEntry.h
@@ -36,6 +36,7 @@ class GenericHashEntry {
   GenericHashEntry *hash_next; /**< Pointer of next hash entry.*/
 
  protected:
+  u_int16_t num_uses;
   bool will_be_purged; /**< Mark this host as candidate for purging.*/
   time_t first_seen;   /**< Time of first seen.*/
   time_t last_seen;    /**< Time of last seen.*/
@@ -97,6 +98,8 @@ class GenericHashEntry {
   inline bool is_ready_to_be_purged() { return(will_be_purged); };
   virtual u_int32_t key()             { return(0);         };  
   virtual char* get_string_key(char *buf, u_int buf_len) { buf[0] = '\0'; return(buf); };
+  void incUses() { num_uses++; }
+  void decUses() { num_uses--; }
 };
 
 #endif /* _GENERIC_HASH_ENTRY_H_ */
diff --git a/include/Host.h b/include/Host.h
index 4cd8adc885..8b04ef9c4a 100644
--- a/include/Host.h
+++ b/include/Host.h
@@ -24,31 +24,26 @@
 
 #include "ntop_includes.h"
 
-#define INTER_FLOW_ACTIVITY_SLOTS 5
-#define INTER_FLOW_ACTIVITY_MAX_INTERVAL 5
-#define INTER_FLOW_ACTIVITY_MAX_CONTINUITY_INTERVAL 20
-
-typedef enum {
-  ifa_facebook_stats = 0,
-  ifa_twitter_stats,
-
-  IFA_STATS_PROTOS_N
-} ifa_stats_protos;
+typedef struct {
+  const Flow *flow;
+  time_t first;
+  time_t last;
+  u_int16_t pkts;
+} InterFlowActivityStats;
 
 class Host : public GenericHost {
  private:
-  u_int8_t mac_address[6];
   u_int32_t asn;
   char *symbolic_name, *country, *city, *asname, os[16], trafficCategory[12], *topSitesKey;
   bool blacklisted_host, drop_all_host_traffic, dump_host_traffic;
   u_int32_t host_quota_mb;
-  u_int16_t num_uses;
   int16_t local_network_id, deviceIfIdx;
   u_int32_t deviceIP;
   int ingress_shaper_id, egress_shaper_id;
   float latitude, longitude;
-  IpAddress *ip;
+  IpAddress ip;
   Mutex *m;
+  Mac *mac;
   time_t nextResolveAttempt, nextSitesUpdate;
 #ifdef NTOPNG_PRO
   CountMinSketch *sent_to_sketch, *rcvd_from_sketch;
@@ -61,13 +56,8 @@ class Host : public GenericHost {
   TrafficStats other_ip_sent, other_ip_rcvd;
   TrafficStats ingress_drops, egress_drops;
   
-  UserActivityStats user_activities;
-  struct {
-    const Flow * flow;
-    time_t first;
-    time_t last;
-    u_int16_t pkts;
-  } ifa_stats[IFA_STATS_PROTOS_N][INTER_FLOW_ACTIVITY_SLOTS];
+  UserActivityStats *user_activities;
+  InterFlowActivityStats *ifa_stats;
   PacketStats sent_stats, recv_stats;
   u_int32_t total_num_flows_as_client, total_num_flows_as_server;
   u_int32_t num_active_flows_as_client, num_active_flows_as_server;
@@ -86,7 +76,7 @@ class Host : public GenericHost {
     u_int32_t pktRetr, pktOOO, pktLost;
   } tcpPacketStats; /* Sent packets */
 
-  void initialize(u_int8_t mac[6], u_int16_t _vlan_id, bool init_all);
+  void initialize(u_int8_t _mac[6], u_int16_t _vlan_id, bool init_all);
   void refreshHTTPBL();
   void computeHostSerial();
   json_object* getJSONObject();
@@ -98,8 +88,7 @@ class Host : public GenericHost {
  public:
   Host(NetworkInterface *_iface);
   Host(NetworkInterface *_iface, char *ipAddress, u_int16_t _vlanId);
-  Host(NetworkInterface *_iface, u_int8_t mac[6], u_int16_t _vlanId);
-  Host(NetworkInterface *_iface, u_int8_t mac[6], u_int16_t _vlanId, IpAddress *_ip);
+  Host(NetworkInterface *_iface, u_int8_t _mac[6], u_int16_t _vlanId, IpAddress *_ip);
   ~Host();
 
   void updateLocal();
@@ -113,17 +102,17 @@ class Host : public GenericHost {
   inline int16_t get_local_network_id()             { return(local_network_id);      };
   inline PacketStats* get_sent_stats()              { return(&sent_stats);           };
   inline PacketStats* get_recv_stats()              { return(&recv_stats);           };
-  inline HTTPstats* getHTTPstats()                  { return(http);     };
+  inline HTTPstats* getHTTPstats()                  { return(http);                  };
   inline HTTPstats* getHTTP()                       { return(http);                  };
-  inline void set_ipv4(u_int32_t _ipv4)             { ip->set_ipv4(_ipv4);           };
-  inline void set_ipv6(struct ndpi_in6_addr *_ipv6) { ip->set_ipv6(_ipv6);           };
-  u_int32_t key();
+  inline void set_ipv4(u_int32_t _ipv4)             { ip.set(_ipv4);                 };
+  inline void set_ipv6(struct ndpi_in6_addr *_ipv6) { ip.set(_ipv6);                 };
+  inline u_int32_t key()                            { return(ip.key());              };
   char* getJSON();
   inline void setOS(char *_os)                 { if(os[0] == '\0') snprintf(os, sizeof(os), "%s", _os); }
-  inline IpAddress* get_ip()                   { return(ip);               }
+  inline IpAddress* get_ip()                   { return(&ip);              }
   void set_mac(char *m);
   inline bool is_blacklisted()                 { return(blacklisted_host); }
-  inline u_int8_t*  get_mac()                  { return(mac_address);      }
+  inline u_int8_t*  get_mac()                  { return(mac ? mac->get_mac() : NULL);      }
   inline char* get_os()                        { return(os);               }
   inline char* get_name()                      { return(symbolic_name);    }
   inline char* get_country()                   { return(country);          }
@@ -133,15 +122,12 @@ class Host : public GenericHost {
   inline int get_egress_shaper_id()            { return(egress_shaper_id);  }
   inline u_int32_t get_asn()                   { return(asn);              }
   inline char*     get_asname()                { return(asname);           }
-  inline bool isPrivateHost()                  { return((ip && ip->isPrivateAddress()) ? true : false); }
+  inline bool isPrivateHost()                  { return(ip.isPrivateAddress()); }
   inline float get_latitude()                  { return(latitude);         }
   inline float get_longitude()                 { return(longitude);        }
-  bool isLocalInterfaceAddress();
-  char* get_mac(char *buf, u_int buf_len, u_int8_t *mac);
+  bool isLocalInterfaceAddress();  
   char* get_name(char *buf, u_int buf_len, bool force_resolution_if_not_found);
-  char* get_string_key(char *buf, u_int buf_len);
-  void incUses() { num_uses++; }
-  void decUses() { num_uses--; }
+  inline char* get_string_key(char *buf, u_int buf_len) { return(ip.print(buf, buf_len)); };
   bool idle();
   void lua(lua_State* vm, patricia_tree_t * ptree, bool host_details,
 	   bool verbose, bool returnHost, bool asListElement,
@@ -149,14 +135,15 @@ class Host : public GenericHost {
   void resolveHostName();
   void setName(char *name);
   void set_host_label(char *label_name);
-  int compare(Host *h);
-  inline bool equal(IpAddress *_ip)  { return(ip && _ip && ip->equal(_ip)); };
+  inline int compare(Host *h) { return(ip.compare(&h->ip)); };
+  inline bool equal(IpAddress *_ip)  { return(_ip && ip.equal(_ip)); };
   void incStats(u_int8_t l4_proto, u_int ndpi_proto,
 		struct site_categories *category,
 		u_int64_t sent_packets, u_int64_t sent_bytes, u_int64_t sent_goodput_bytes,
 		u_int64_t rcvd_packets, u_int64_t rcvd_bytes, u_int64_t rcvd_goodput_bytes);
   void incHitter(Host *peer, u_int64_t sent_bytes, u_int64_t rcvd_bytes);
   void updateHostTrafficPolicy(char *key);
+  inline void incMacStats(bool sentBytes, u_int pkt_len) { if(mac) { if(sentBytes) mac->incSentStats(pkt_len); else mac->incRcvdStats(pkt_len); } };
   char* serialize();
   void  serialize2redis();
   bool  deserialize(char *json_str, char *key);
@@ -199,8 +186,9 @@ class Host : public GenericHost {
   void incrVisitedWebSite(char *hostname);
   const UserActivityCounter * getActivityBytes(UserActivityID id);
   void incActivityBytes(UserActivityID id, u_int64_t upbytes, u_int64_t downbytes, u_int64_t bgbytes);
-  void incIfaPackets(ifa_stats_protos proto, const Flow * flow, time_t when);
-  void getIfaStats(ifa_stats_protos proto, time_t when, int * count, u_int32_t * packets, time_t * max_diff);
+  void incIfaPackets(InterFlowActivityProtos proto, const Flow * flow, time_t when);
+  void getIfaStats(InterFlowActivityProtos proto, time_t when, int * count, u_int32_t * packets, time_t * max_diff);
+  inline UserActivityStats* get_user_activities() { return(user_activities); }
 };
 
 #endif /* _HOST_H_ */
diff --git a/include/HostActivityRetriever.h b/include/HostActivityRetriever.h
new file mode 100644
index 0000000000..d45164aba7
--- /dev/null
+++ b/include/HostActivityRetriever.h
@@ -0,0 +1,36 @@
+/*
+ *
+ * (C) 2013-16 - ntop.org
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ */
+
+#ifndef _HOST_ACTIVITY_RETRIEVER_H_
+#define _HOST_ACTIVITY_RETRIEVER_H_
+
+#include "ntop_includes.h"
+
+class HostActivityRetriever {
+public:
+  IpAddress search;
+  bool found;
+  UserActivityCounter counters[UserActivitiesN];
+
+  HostActivityRetriever(const char * ip) { search.set((char *)ip), found = false; };
+};
+
+#endif /* _HOST_ACTIVITY_RETRIEVER_H_ */
diff --git a/include/HostHash.h b/include/HostHash.h
index d7bb6d6913..3635cb0949 100644
--- a/include/HostHash.h
+++ b/include/HostHash.h
@@ -32,7 +32,7 @@ class HostHash : public GenericHash {
  public:
   HostHash(NetworkInterface *iface, u_int _num_hashes, u_int _max_hash_size);
 
-  Host* get(u_int16_t vlanId, const u_int8_t mac[6]);
+  // Host* get(u_int16_t vlanId, const u_int8_t mac[6]);
   Host* get(u_int16_t vlanId, IpAddress *key);
 
   void incNumHTTPEntries();  
diff --git a/include/IpAddress.h b/include/IpAddress.h
index ac27280292..34b3602670 100644
--- a/include/IpAddress.h
+++ b/include/IpAddress.h
@@ -48,31 +48,27 @@ class IpAddress {
   
  public:
   IpAddress();
-  IpAddress(char *string);
-  IpAddress(IpAddress *ip);
-  IpAddress(u_int32_t _ipv4);
-  IpAddress(struct ndpi_in6_addr *_ipv6);
 
   bool isEmpty();
   inline void reset()                                 { memset(&addr, 0, sizeof(addr));               }
   inline bool isIPv4()                                { return((addr.ipVersion == 4) ? true : false); }
-  inline bool isIPv6()                                { return((addr.ipVersion == 6) ? true : false); }
-  inline void set_ipv4(u_int32_t _ipv4)               { addr.ipVersion = 4, addr.ipType.ipv4 = _ipv4; compute_key(); }
-  inline void set_ipv6(struct ndpi_in6_addr *_ipv6)   { addr.ipVersion = 6, memcpy(&addr.ipType.ipv6, _ipv6, sizeof(struct ndpi_in6_addr)); compute_key(); }
+  inline bool isIPv6()                                { return((addr.ipVersion == 6) ? true : false); }  
   inline u_int32_t get_ipv4()                         { return((addr.ipVersion == 4) ? addr.ipType.ipv4 : 0);     }
   inline struct ndpi_in6_addr* get_ipv6()             { return((addr.ipVersion == 6) ? &addr.ipType.ipv6 : NULL); }
   inline struct ipAddress* getIP()                    { return(&addr); };
   inline bool equal(u_int32_t ipv4_addr)              { if((addr.ipVersion == 4) && (addr.ipType.ipv4 == ipv4_addr)) return(true); else return(false); };
   inline bool equal(struct ndpi_in6_addr *ip6_addr)   { if((addr.ipVersion == 6) && (memcmp(&addr.ipType.ipv6, ip6_addr, sizeof(struct ndpi_in6_addr)) == 0)) return(true); else return(false); };
   inline bool equal(IpAddress *_ip)                   { return(this->compare(_ip) == 0); };
-
-  void set_from_string(char *string);
   int compare(IpAddress *ip);
-  inline u_int32_t key()                               { return(ip_key);         };
-  void set(IpAddress *ip);
-  inline bool isPrivateAddress()                       { return(addr.privateIP); };
-  inline bool isMulticastAddress()                     { return(addr.multicastIP); };
-  inline bool isBroadcastAddress()                     { return(addr.broadcastIP); };
+  inline u_int32_t key()                              { return(ip_key);         };
+  inline void set(u_int32_t _ipv4)                    { addr.ipVersion = 4, addr.ipType.ipv4 = _ipv4; compute_key(); }
+  inline void set(struct ndpi_in6_addr *_ipv6)        { addr.ipVersion = 6, memcpy(&addr.ipType.ipv6, _ipv6, sizeof(struct ndpi_in6_addr)); 
+                                                        addr.privateIP = false; compute_key(); }
+  inline void set(IpAddress *ip)                      { memcpy(&addr, &ip->addr, sizeof(struct ipAddress)); ip_key = ip->ip_key; };
+  void set(char *ip);  
+  inline bool isPrivateAddress()                      { return(addr.privateIP); };
+  inline bool isMulticastAddress()                    { return(addr.multicastIP); };
+  inline bool isBroadcastAddress()                    { return(addr.broadcastIP); };
   char* print(char *str, u_int str_len, u_int8_t bitmask = 0);
   bool isLocalHost(int16_t *network_id);
   bool isLocalInterfaceAddress();
diff --git a/include/Mac.h b/include/Mac.h
new file mode 100644
index 0000000000..cb9e05bf19
--- /dev/null
+++ b/include/Mac.h
@@ -0,0 +1,50 @@
+/*
+ *
+ * (C) 2013-16 - ntop.org
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ */
+
+#ifndef _MAC_H_
+#define _MAC_H_
+
+#include "ntop_includes.h"
+
+class Mac : public GenericHashEntry {
+ private:
+  u_int8_t mac[6];
+  u_int16_t vlan_id;
+  TrafficStats sent, rcvd;
+  
+ public:
+  Mac(NetworkInterface *_iface, u_int8_t _mac[6], u_int16_t _vlanId);
+  ~Mac();
+
+  inline u_int8_t* get_mac()     { return(mac);     }
+  inline u_int16_t get_vlan_id() { return(vlan_id); }
+
+  inline void incSentStats(u_int pkt_len)  { sent.incStats(pkt_len); }
+  inline void incRcvdStats(u_int pkt_len)  { rcvd.incStats(pkt_len); }
+
+  bool idle();
+  bool isIdle(u_int max_idleness);
+
+  inline u_int32_t key()  { return(mac[0]+mac[1]+mac[2]+mac[3]+mac[4]+mac[5]); };
+  inline char* get_string_key(char *buf, u_int buf_len) { return(Utils::formatMac(mac, buf, buf_len)); }
+};
+
+#endif /* _MAC_H_ */
diff --git a/include/MacHash.h b/include/MacHash.h
new file mode 100644
index 0000000000..dbb22fa08d
--- /dev/null
+++ b/include/MacHash.h
@@ -0,0 +1,37 @@
+/*
+ *
+ * (C) 2013-16 - ntop.org
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ */
+
+#ifndef _MAC_HASH_H_
+#define _MAC_HASH_H_
+
+#include "ntop_includes.h"
+ 
+class MacHash : public GenericHash {
+ private:
+  Mutex m;
+
+ public:
+  MacHash(NetworkInterface *iface, u_int _num_hashes, u_int _max_hash_size);
+
+  Mac* get(u_int16_t vlanId, const u_int8_t mac[6]);
+};
+
+#endif /* _MAC_HASH_H_ */
diff --git a/include/NetworkInterface.h b/include/NetworkInterface.h
index a925197668..6bbde3655c 100644
--- a/include/NetworkInterface.h
+++ b/include/NetworkInterface.h
@@ -1,4 +1,4 @@
-/*
+ /*
  *
  * (C) 2013-16 - ntop.org
  *
@@ -31,6 +31,8 @@ class Flow;
 class FlowHash;
 class Host;
 class HostHash;
+class Mac;
+class MacHash;
 class DB;
 class Paginator;
 
@@ -86,8 +88,12 @@ class NetworkInterface {
   TcpPacketStats tcpPacketStats;
 
   u_int64_t zmq_initial_bytes, zmq_initial_pkts;
+
+  /* Mac */
+  MacHash *macs_hash; /**< Hash used to store MAC information. */
+
   /* Hosts */
-  HostHash *hosts_hash; /**< Hash used to memorize the hosts information. */
+  HostHash *hosts_hash; /**< Hash used to store hosts information. */
   bool purge_idle_flows_hosts, sprobe_interface, inline_interface,
     dump_all_traffic, dump_to_tap, dump_to_disk, dump_unknown_traffic, dump_security_packets;
   DB *db;
@@ -292,18 +298,18 @@ class NetworkInterface {
 
   void purgeIdle(time_t when);
   u_int purgeIdleFlows();
-  u_int purgeIdleHosts();
+  u_int purgeIdleHostsMacs();
 
   u_int64_t getNumPackets();
   u_int64_t getNumBytes();
   u_int getNumPacketDrops();
   u_int getNumFlows();
   u_int getNumHosts();
+  u_int getNumMacs();
   u_int getNumHTTPHosts();
 
   void runHousekeepingTasks();
-  Host* findHostByMac(u_int8_t mac[6], u_int16_t vlanId,
-		      bool createIfNotPresent);
+  Mac*  getMac(u_int8_t _mac[6], u_int16_t vlanId, bool createIfNotPresent);
   Host* getHost(char *host_ip, u_int16_t vlan_id);
   bool getHostInfo(lua_State* vm, patricia_tree_t *allowed_hosts, char *host_ip, u_int16_t vlan_id);
   bool loadHostAlertPrefs(lua_State* vm, patricia_tree_t *allowed_hosts, char *host_ip, u_int16_t vlan_id);
@@ -350,6 +356,7 @@ class NetworkInterface {
 		      char *host_ip, u_int16_t vlan_id);
 
   inline HostHash* get_hosts_hash()  { return(hosts_hash);       }
+  inline MacHash*  get_macs_hash()   { return(macs_hash);        }
   inline bool is_bridge_interface()  { return(bridge_interface); }
   inline const char* getLocalIPAddresses() { return(ip_addresses.c_str()); }
   void addInterfaceAddress(char *addr);
diff --git a/include/Utils.h b/include/Utils.h
index f24c53c43b..6d8df8f2db 100755
--- a/include/Utils.h
+++ b/include/Utils.h
@@ -72,7 +72,6 @@ class Utils {
   static ticks getticks();
   static char* getURL(char *url, char *buf, u_int buf_len);
   static bool discardOldFilesExceeding(const char *path, const unsigned long max_size);
-  static char* macaddr_str (const char *mac, char *buf);
   static u_int64_t macaddr_int(const u_int8_t *mac);
   static void readMac(char *ifname, dump_mac_t mac_addr);
   static u_int32_t getMaxIfSpeed(const char *ifname);
@@ -86,6 +85,7 @@ class Utils {
   static void xor_encdec(u_char *data, int data_len, u_char *key);
   static bool isPrintableChar(u_char c);
   static const char* flowstatus2str(FlowStatus s);
+  static char* formatMac(u_int8_t *mac, char *buf, u_int buf_len);
 };
 
 #endif /* _UTILS_H_ */
diff --git a/include/ntop_defines.h b/include/ntop_defines.h
index f0e62d6c73..71c8b6238b 100644
--- a/include/ntop_defines.h
+++ b/include/ntop_defines.h
@@ -553,4 +553,8 @@
 #define _COMPILE_TIME_ASSERT2(X,L) _COMPILE_TIME_ASSERT3(X,L)
 #define COMPILE_TIME_ASSERT(X)    _COMPILE_TIME_ASSERT2(X,__LINE__)
 
+#define INTER_FLOW_ACTIVITY_SLOTS 5
+#define INTER_FLOW_ACTIVITY_MAX_INTERVAL 5
+#define INTER_FLOW_ACTIVITY_MAX_CONTINUITY_INTERVAL 20
+
 #endif /* _NTOP_DEFINES_H_ */
diff --git a/include/ntop_includes.h b/include/ntop_includes.h
index 117b582c69..ef0753dc13 100644
--- a/include/ntop_includes.h
+++ b/include/ntop_includes.h
@@ -190,6 +190,7 @@ using namespace std;
 #include "MySQLDB.h"
 #include "TcpFlowStats.h"
 #include "InterfaceStatsHash.h"
+#include "HostActivityRetriever.h"
 #include "NetworkInterface.h"
 #include "PcapInterface.h"
 #include "ViewInterface.h"
@@ -220,10 +221,12 @@ using namespace std;
 #include "Flashstart.h"
 #include "GenericHost.h"
 #include "CategoryStats.h"
+#include "Mac.h"
 #include "Host.h"
 #include "ActivityFilters.h"
 #include "Flow.h"
 #include "FlowHash.h"
+#include "MacHash.h"
 #include "HostHash.h"
 #include "PeriodicActivities.h"
 #include "Lua.h"
diff --git a/include/ntop_typedefs.h b/include/ntop_typedefs.h
index 9f4dd6d54e..cda1d0ceb6 100644
--- a/include/ntop_typedefs.h
+++ b/include/ntop_typedefs.h
@@ -238,4 +238,10 @@ typedef enum {
 		  */
 } UserActivityID;
 
+typedef enum {
+  ifa_facebook_stats = 0,
+  ifa_twitter_stats,
+  IFA_STATS_PROTOS_N
+} InterFlowActivityProtos;
+
 #endif /* _NTOP_TYPEDEFS_H_ */
diff --git a/scripts/lua/admin/prefs.lua b/scripts/lua/admin/prefs.lua
index 7161ab1ab0..011fa9965c 100644
--- a/scripts/lua/admin/prefs.lua
+++ b/scripts/lua/admin/prefs.lua
@@ -403,6 +403,19 @@ function printStatsRrds()
 			    "to keep application protocol statistics at the cost of using more disk space.",
 			 "On", "1", "success", "Off", "0", "danger", "toggle_local_ndpi", "ntopng.prefs.host_ndpi_rrd_creation", "0")
 
+ local toggle_local_activity = "toggle_local_activity"
+  local activityPrefsToSwitch = {"local_activity_prefs",
+    "host_activity_rrd_raw_hours", "id_input_host_activity_rrd_raw_hours",
+    "host_activity_rrd_1h_days", "id_input_host_activity_rrd_1h_days",
+    "host_activity_rrd_1d_days", "id_input_host_activity_rrd_1d_days"}
+
+  if prefs.is_flow_activity_enabled then
+    toggleTableButtonPrefs("Activities Timeseries",
+			 "Toggle the creation of activities timeseries for local hosts and networks. Turn it off to save storage space.",
+  	 	         "On", "1", "success", "Off", "0", "danger", toggle_local_activity, "ntopng.prefs.host_activity_rrd_creation", "0",
+                         false, activityPrefsToSwitch)
+  end
+
   local info = ntop.getInfo()
   toggleTableButtonPrefs("Flow Devices Timeseries",
 			 "Toggle the creation of bytes timeseries for each port of the sFlow/NetFlow devices. For each device port" ..
diff --git a/scripts/lua/get_grouped_hosts_data.lua b/scripts/lua/get_grouped_hosts_data.lua
index ceb95389f8..fce11bdd05 100644
--- a/scripts/lua/get_grouped_hosts_data.lua
+++ b/scripts/lua/get_grouped_hosts_data.lua
@@ -104,12 +104,8 @@ function print_single_group(value)
       end      
    elseif (group_col == "local_network_id" or network_n ~= nil) then
       print("hosts_stats.lua?network="..tostring(value["id"]).."'>")
-   elseif (group_col == "antenna_mac") then
-      print("hosts_stats.lua?antenna_mac="..value["id"].."'>")
    elseif (group_col == "mac") then
       print("hosts_stats.lua?mac="..value["name"].."'>")
-      --PRINT
-      -- io.write("ID = "..value["id"]..'\n')
    else
       print("hosts_stats.lua'>")
    end
@@ -132,7 +128,7 @@ function print_single_group(value)
       end
       print('", ')
 
-   elseif((group_col == "mac") or (group_col == "antenna_mac")) then
+   elseif(group_col == "mac") then
       print(get_symbolic_mac(value["name"])..'</A>", ')
    elseif(group_col == "country" and value["id"] == "Uncategorized") then
       print('</A>'..value["id"]..'", ')
diff --git a/scripts/lua/get_hosts_data.lua b/scripts/lua/get_hosts_data.lua
index 4ae360fa22..6b7ab4dc57 100644
--- a/scripts/lua/get_hosts_data.lua
+++ b/scripts/lua/get_hosts_data.lua
@@ -28,7 +28,6 @@ vlan         = _GET["vlan"]
 network      = _GET["network"]
 country      = _GET["country"]
 os_    	     = _GET["os"]
-antenna_mac  = _GET["antenna_mac"]
 mac          = _GET["mac"]
 
 -- table_id = _GET["table"]
@@ -98,8 +97,6 @@ interface.select(ifname)
 to_skip = (currentPage-1) * perPage
 
 if(sortOrder == "desc") then sOrder = false else sOrder = true end
--- if((mac ~= nil) or (antenna_mac ~= nil) or (mode == "local")) then
-
 
 hosts_retrv_function = interface.getHostsInfo
 if mode == "local" then
@@ -275,7 +272,6 @@ for _key, _value in pairsByKeys(vals, funct) do
 ((asn == nil) or (asn == tostring(hosts_stats[key]["asn"]))) and
 ((os_ == nil) or (os_ == tostring(hosts_stats[key]["os"]))) and
 ((country == nil) or (country == tostring(hosts_stats[key]["country"]))) and
-((antenna_mac == nil) or (antenna_mac == tostring(hosts_stats[key]["antenna_mac"]))) and
 ((mac == nil) or (mac == tostring(hosts_stats[key]["mac"]))) and
 ((vlan == nil) or (vlan == tostring(hosts_stats[key]["vlan"]))) and
 ((network == nil) or (network == tostring(hosts_stats[key]["local_network_id"])))) then
diff --git a/scripts/lua/host_details.lua b/scripts/lua/host_details.lua
index fb9819c315..cfab21c4a5 100644
--- a/scripts/lua/host_details.lua
+++ b/scripts/lua/host_details.lua
@@ -36,6 +36,8 @@ is_packetdump_enabled = isLocalPacketdumpEnabled()
 host = nil
 family = nil
 
+prefs = ntop.getPrefs()
+
 local hostkey = hostinfo2hostkey(host_info, nil, true --[[ force show vlan --]])
 
 if((host_name == nil) or (host_ip == nil)) then
@@ -214,12 +216,14 @@ else
    end
 end
 
-if(page == "activities") then
-  print("<li class=\"active\"><a href=\"#\">Activities</a></li>\n")
-else
-   if interface.isPcapDumpInterface() == false and host["ip"] ~= nil then
+if(prefs.is_flow_activity_enabled) then
+  if(page == "activities") then
+    print("<li class=\"active\"><a href=\"#\">Activities</a></li>\n")
+  else
+    if interface.isPcapDumpInterface() == false and host["ip"] ~= nil then
       print("<li><a href=\""..url.."&page=activities\">Activities</a></li>")
-   end
+    end
+  end
 end
 
 if(page == "dns") then
diff --git a/scripts/lua/hosts_stats.lua b/scripts/lua/hosts_stats.lua
index a13a9943b7..9e7fba3697 100644
--- a/scripts/lua/hosts_stats.lua
+++ b/scripts/lua/hosts_stats.lua
@@ -17,7 +17,6 @@ asn          = _GET["asn"]
 vlan         = _GET["vlan"]
 network      = _GET["network"]
 country      = _GET["country"]
-antenna_mac  = _GET["antenna_mac"]
 mac          = _GET["mac"]
 os_   	     = _GET["os"]
 community    = _GET["community"]
@@ -114,10 +113,6 @@ else
    network_url  = ""
 end
 
-if(antenna_mac ~= nil) then
-   print('&antenna_mac='..antenna_mac)
-end
-
 if(mac ~= nil) then
    print('&mac='..mac)
 end
@@ -133,18 +128,10 @@ if(prefs.is_categorization_enabled) then print ('host_rows_option["categorizatio
 if(prefs.is_httpbl_enabled) then print ('host_rows_option["httpbl"] = true;\n') end
 if(show_vlan) then print ('host_rows_option["vlan"] = true;\n') end
 
-if(antenna_mac ~= nil) then
-   am = "antenna_mac="..antenna_mac
-   am_str = " [Antenna "..antenna_mac.."]"
-else
-   am = nil
-   am_str = ""
-end
-
 print [[
 	 host_rows_option["ip"] = true;
 	 $("#table-hosts").datatable({
-			title: "Hosts List]] print(am_str) print [[",
+			title: "Hosts List",
 			url: url_update ,
 	 ]]
 
@@ -179,7 +166,6 @@ if(mode == "all") then
 	elseif ( asninfo ~= "" ) then print('title: "All '..protocol..' '..network_name..' Hosts'..asninfo..'",\n')
 	elseif ( mac ~= "" ) then print('title: "All local '..protocol..' '..network_name..' Hosts'..mac..'",\n')
 	elseif ( os_ ~= "" ) then print('title: "All '..os_..' Hosts",\n') 
-	elseif ( am_str ~= "" ) then print('title: "All '..os_..' Hosts'..am_str..'",\n') 
 	else print('title: "All '..protocol..' '..network_name..' Hosts'..asninfo..'",\n')
 	end
 elseif(mode == "local") then
@@ -187,7 +173,6 @@ elseif(mode == "local") then
 	elseif ( asninfo ~= "" ) then print('title: "Local '..protocol..' '..network_name..' Hosts'..asninfo..'",\n')
 	elseif ( mac ~= "" ) then print('title: "Local local '..protocol..' '..network_name..' Hosts'..mac..'",\n')
 	elseif ( os_ ~= "" ) then print('title: "Local Hosts'..os_..' Hosts",\n') 
-	elseif ( am_str ~= "" ) then print('title: "Local '..protocol..' '..network_name..' Hosts'..country..am_str..'",\n')
 	else  print('title: "Local '..protocol..' '..network_name..' Hosts'..country..'",\n')
 	end
 elseif(mode == "remote") then
@@ -195,7 +180,6 @@ elseif(mode == "remote") then
 	elseif ( asninfo ~= "" ) then print('title: "Remote '..protocol..' '..network_name..' Hosts'..asninfo..'",\n')
 	elseif ( mac ~= "" ) then print('title: "Remote local '..protocol..' '..network_name..' Hosts'..mac..'",\n')
 	elseif ( os_ ~= "" ) then print('title: "Remote '..os_..' Hosts",\n') 
-	elseif ( am_str ~= "" ) then print('title: "Remote '..protocol..' '..network_name..' Hosts'..country..am_str..'",\n')
 	else print('title: "Remote '..protocol..' '..network_name..' Hosts'..country..'",\n')
 	end
 else
diff --git a/scripts/lua/inc/menu.lua b/scripts/lua/inc/menu.lua
index cef88e68cc..bb7894ef08 100644
--- a/scripts/lua/inc/menu.lua
+++ b/scripts/lua/inc/menu.lua
@@ -151,10 +151,6 @@ print(ntop.getHttpPrefix())
 print [[/lua/hosts_matrix.lua"><i class="fa fa-th-large"></i> Local Flow Matrix</a></li>
    ]]
 
-if(_ifstats["has_mesh_networks_traffic"]) then
-   print [[ <li><a href="]] print(ntop.getHttpPrefix()) print [[/lua/mesh_antenna_stats.lua"><i class="fa fa-wifi"></i> Mesh Antenna Stats</a></li> ]]
-end
-
 print("</ul> </li>")
 
 -- Devices
diff --git a/scripts/lua/mesh_antenna_stats.lua b/scripts/lua/mesh_antenna_stats.lua
deleted file mode 100644
index ee4dff9695..0000000000
--- a/scripts/lua/mesh_antenna_stats.lua
+++ /dev/null
@@ -1,73 +0,0 @@
---
--- (C) 2013-16 - ntop.org
---
-
-dirs = ntop.getDirs()
-package.path = dirs.installdir .. "/scripts/lua/modules/?.lua;" .. package.path
-
-require "lua_utils"
-
-sendHTTPHeader('text/html; charset=iso-8859-1')
-
-if (group_col == nil) then
-   group_col = "network"
-end
-
-ntop.dumpFile(dirs.installdir .. "/httpdocs/inc/header.inc")
-
-active_page = "hosts"
-dofile(dirs.installdir .. "/scripts/lua/inc/menu.lua")
-
-print [[
-      <hr>
-      <div id="table-network"></div>
-	 <script>
-	 var url_update = "]]
-print (ntop.getHttpPrefix())
-print [[/lua/get_grouped_hosts_data.lua?grouped_by=antenna_mac]]
-
-print ('";')
-ntop.dumpFile(dirs.installdir .. "/httpdocs/inc/network_stats_id.inc")
-
-print [[
-	 $("#table-network").datatable({
-                        title: "Mesh Network Antenna List",
-			url: url_update ,
-	 ]]
-
-print ('rowCallback: function ( row ) { return network_table_setID(row); },')
-
--- Set the preference table
-preference = tablePreferences("rows_number",_GET["perPage"])
-if (preference ~= "") then print ('perPage: '..preference.. ",\n") end
-
--- Automatic default sorted. NB: the column must exist.
-print ('sort: [ ["' .. getDefaultTableSort("network") ..'","' .. getDefaultTableSortOrder("network").. '"] ],')
-
-
-print [[
-	       showPagination: true,
-	        columns: [
-           {
-                                title: "Key",
-                                field: "key",
-                                hidden: true,
-                                css: {
-                                   textAlign: 'center'
-                                }
-           },
-                         {
-			     title: "Antenna MAC",
-				 field: "column_id",
-				 sortable: true,
-                             css: {
-			        textAlign: 'left'
-			     }
-				 },
-			  ]]
-
-
-ntop.dumpFile(dirs.installdir .. "/httpdocs/inc/network_stats_top.inc")
-
-ntop.dumpFile(dirs.installdir .. "/httpdocs/inc/hosts_stats_bottom.inc")
-dofile(dirs.installdir .. "/scripts/lua/inc/footer.lua")
diff --git a/src/ActivityFilters.cpp b/src/ActivityFilters.cpp
index d9a6be5cf1..684b4f6e32 100644
--- a/src/ActivityFilters.cpp
+++ b/src/ActivityFilters.cpp
@@ -321,7 +321,7 @@ static bool activity_filter_fun_interflow(const activity_filter_config * config,
   int f_count = 0;
   u_int32_t f_pkts = 0;
   time_t max_duration = 0;
-  ifa_stats_protos proto;
+  InterFlowActivityProtos proto;
   bool rv = false;
 
   switch(flow->get_detected_protocol().protocol) {
diff --git a/src/Flow.cpp b/src/Flow.cpp
index 11f5aee03f..7510fe3dbe 100644
--- a/src/Flow.cpp
+++ b/src/Flow.cpp
@@ -1245,7 +1245,7 @@ void Flow::lua(lua_State* vm, patricia_tree_t * ptree,
       lua_push_str_table_entry(vm, "cli.host", src->get_name(buf, sizeof(buf), false));
       lua_push_int_table_entry(vm, "cli.source_id", src->getSourceId());
       lua_push_str_table_entry(vm, "cli.ip", src->get_ip()->print(buf, sizeof(buf)));
-      lua_push_str_table_entry(vm, "cli.mac", Utils::macaddr_str((char*)src->get_mac(), buf));
+      lua_push_str_table_entry(vm, "cli.mac", Utils::formatMac(src->get_mac(), buf, sizeof(buf)));
       lua_push_int_table_entry(vm, "cli.key", src->key());
 
       lua_push_bool_table_entry(vm, "cli.systemhost", src->isSystemHost());
@@ -1263,7 +1263,7 @@ void Flow::lua(lua_State* vm, patricia_tree_t * ptree,
       lua_push_str_table_entry(vm, "srv.host", dst->get_name(buf, sizeof(buf), false));
       lua_push_int_table_entry(vm, "srv.source_id", src->getSourceId());
       lua_push_str_table_entry(vm, "srv.ip", dst->get_ip()->print(buf, sizeof(buf)));
-      lua_push_str_table_entry(vm, "srv.mac", Utils::macaddr_str((char*)dst->get_mac(), buf));
+      lua_push_str_table_entry(vm, "srv.mac", Utils::formatMac(dst->get_mac(), buf, sizeof(buf)));
       lua_push_int_table_entry(vm, "srv.key", dst->key());
       lua_push_bool_table_entry(vm, "srv.systemhost", dst->isSystemHost());
       lua_push_bool_table_entry(vm, "srv.allowed_host", dst_match);
@@ -1618,9 +1618,9 @@ json_object* Flow::flow2json(bool partial_dump) {
 
     // MAC addresses are set only when dumping to ES to optimize space consumption
     json_object_object_add(my_object, Utils::jsonLabel(IN_SRC_MAC, "IN_SRC_MAC", jsonbuf, sizeof(jsonbuf)),
-			   json_object_new_string(Utils::macaddr_str((char*)cli_host->get_mac(), buf)));
+			   json_object_new_string(Utils::formatMac(cli_host->get_mac(), buf, sizeof(buf))));
     json_object_object_add(my_object, Utils::jsonLabel(OUT_DST_MAC, "OUT_DST_MAC", jsonbuf, sizeof(jsonbuf)),
-			   json_object_new_string(Utils::macaddr_str((char*)srv_host->get_mac(), buf)));
+			   json_object_new_string(Utils::formatMac(srv_host->get_mac(), buf, sizeof(buf))));
   }
 
   if(cli_host->get_ip()) {
@@ -1912,9 +1912,11 @@ void Flow::incStats(bool cli2srv_direction, u_int pkt_len,
 
   if(cli2srv_direction) {
     cli2srv_packets++, cli2srv_bytes += pkt_len, cli2srv_goodput_bytes += payload_len;
-    cli_host->get_sent_stats()->incStats(pkt_len), srv_host->get_recv_stats()->incStats(pkt_len);
+    cli_host->incMacStats(true, pkt_len), srv_host->incMacStats(false, pkt_len),
+      cli_host->get_sent_stats()->incStats(pkt_len), srv_host->get_recv_stats()->incStats(pkt_len);
   } else {
     srv2cli_packets++, srv2cli_bytes += pkt_len, srv2cli_goodput_bytes += payload_len;
+    cli_host->incMacStats(false, pkt_len), srv_host->incMacStats(true, pkt_len),
     cli_host->get_recv_stats()->incStats(pkt_len), srv_host->get_sent_stats()->incStats(pkt_len);
   }
 
diff --git a/src/GenericHashEntry.cpp b/src/GenericHashEntry.cpp
index 8db04eccd7..e9aedc5459 100644
--- a/src/GenericHashEntry.cpp
+++ b/src/GenericHashEntry.cpp
@@ -24,7 +24,8 @@
 /* ***************************************** */
 
 GenericHashEntry::GenericHashEntry(NetworkInterface *_iface) {
-  hash_next = NULL, iface = _iface, first_seen = last_seen = 0, will_be_purged = false;
+  hash_next = NULL, iface = _iface, first_seen = last_seen = 0, 
+    will_be_purged = false, num_uses = 0;;
 }
 
 /* ***************************************** */
diff --git a/src/Grouper.cpp b/src/Grouper.cpp
index 4731a32a15..8648b174fc 100644
--- a/src/Grouper.cpp
+++ b/src/Grouper.cpp
@@ -117,7 +117,7 @@ int8_t Grouper::newGroup(Host *h) {
 
   case column_mac:
     group_id_i = Utils::macaddr_int(h->get_mac());
-    group_label = strdup(Utils::macaddr_str((char*)h->get_mac(), buf));
+    group_label = strdup(Utils::formatMac(h->get_mac(), buf, sizeof(buf)));
     break;
 
   case column_country:
diff --git a/src/Host.cpp b/src/Host.cpp
index 7492df0cf0..5487914c8e 100644
--- a/src/Host.cpp
+++ b/src/Host.cpp
@@ -24,32 +24,22 @@
 /* *************************************** */
 
 Host::Host(NetworkInterface *_iface) : GenericHost(_iface) {
-  ip = new IpAddress();
   initialize(NULL, 0, false);
 }
 
 /* *************************************** */
 
 Host::Host(NetworkInterface *_iface, char *ipAddress, u_int16_t _vlanId) : GenericHost(_iface) {
-  ip = new IpAddress(ipAddress);
-  if (ip && ip->isEmpty()) free(ip), ip = NULL;
+  ip.set(ipAddress);
   initialize(NULL, _vlanId, true);
 }
 
 /* *************************************** */
 
-Host::Host(NetworkInterface *_iface, u_int8_t mac[6],
+Host::Host(NetworkInterface *_iface, u_int8_t _mac[6],
 	   u_int16_t _vlanId, IpAddress *_ip) : GenericHost(_iface) {
-  ip = new IpAddress(_ip);
-  initialize(mac, _vlanId, true);
-}
-
-/* *************************************** */
-
-Host::Host(NetworkInterface *_iface, u_int8_t mac[6],
-	   u_int16_t _vlanId) : GenericHost(_iface) {
-  ip = NULL;
-  initialize(mac, _vlanId, true);
+  ip.set(_ip);
+  initialize(_mac, _vlanId, true);
 }
 
 /* *************************************** */
@@ -65,12 +55,13 @@ Host::~Host() {
     ntop->getRedis()->rename(topSitesKey, oldk);
   }
 
-  if(ip && (!ip->isEmpty())) dumpStats(false);
+  if(!ip.isEmpty()) dumpStats(false);
 
   // ntop->getTrace()->traceEvent(TRACE_NORMAL, "Deleting %s (%s)", k, localHost ? "local": "remote");
 
   serialize2redis(); /* possibly dumps counters and data to redis */
   
+  if(mac) mac->decUses();
 #ifdef NTOPNG_PRO
   if(sent_to_sketch)   delete sent_to_sketch;
   if(rcvd_from_sketch) delete rcvd_from_sketch;
@@ -78,15 +69,15 @@ Host::~Host() {
 
   if(dns)  delete dns;
   if(http) delete http;
-
-  if(symbolic_name)  free(symbolic_name);
-  if(country)        free(country);
-  if(city)           free(city);
-  if(asname)         free(asname);
-  if(categoryStats)  delete categoryStats;
+  if(user_activities) delete user_activities;
+  if(ifa_stats)       delete ifa_stats;
+  if(symbolic_name)   free(symbolic_name);
+  if(country)         free(country);
+  if(city)            free(city);
+  if(asname)          free(asname);
+  if(categoryStats)   delete categoryStats;
   if(syn_flood_attacker_alert) delete syn_flood_attacker_alert;
   if(syn_flood_victim_alert)   delete syn_flood_victim_alert;
-  if(ip) delete ip;
   if(m) delete m;
   if(topSitesKey) free(topSitesKey);
 }
@@ -95,7 +86,7 @@ Host::~Host() {
 
 void Host::set_host_label(char *label_name) {
   if(label_name) {
-    char buf[64], *host = ip->print(buf, sizeof(buf));
+    char buf[64], *host = ip.print(buf, sizeof(buf));
 
     ntop->getRedis()->hashSet((char*)HOST_LABEL_NAMES, host, label_name);
   }
@@ -104,22 +95,20 @@ void Host::set_host_label(char *label_name) {
 /* *************************************** */
 
 void Host::computeHostSerial() {
-  if(ip
-     && iface
-     && Utils::dumpHostToDB(ip, ntop->getPrefs()->get_dump_hosts_to_db_policy())) {
+  if(iface && Utils::dumpHostToDB(&ip, ntop->getPrefs()->get_dump_hosts_to_db_policy())) {
     if(host_serial) {
       char buf[64];
 
       /* We need to reconfirm the id (e.g. after a day wrap) */
-      ntop->getRedis()->setHostId(iface, NULL, ip->print(buf, sizeof(buf)), host_serial);
+      ntop->getRedis()->setHostId(iface, NULL, ip.print(buf, sizeof(buf)), host_serial);
     } else
-      host_serial = ntop->getRedis()->addHostToDBDump(iface, ip, NULL);
+      host_serial = ntop->getRedis()->addHostToDBDump(iface, &ip, NULL);
   }
 }
 
 /* *************************************** */
 
-void Host::initialize(u_int8_t mac[6], u_int16_t _vlanId, bool init_all) {
+void Host::initialize(u_int8_t _mac[6], u_int16_t _vlanId, bool init_all) {
   char key[64], redis_key[128], *k;
   char buf[64], host[96];
 
@@ -127,9 +116,8 @@ void Host::initialize(u_int8_t mac[6], u_int16_t _vlanId, bool init_all) {
   sent_to_sketch = rcvd_from_sketch = NULL;
 #endif
 
-  if(mac) memcpy(mac_address, mac, 6); else memset(mac_address, 0, 6);
-
-  //if(_vlanId > 0) ntop->getTrace()->traceEvent(TRACE_NORMAL, "VLAN => %d", _vlanId);
+  if((mac = iface->getMac(_mac, _vlanId, true)) != NULL)
+    mac->incUses();
 
   drop_all_host_traffic = false, dump_host_traffic = false,
     deviceIP = 0, deviceIfIdx = 0;
@@ -151,106 +139,103 @@ void Host::initialize(u_int8_t mac[6], u_int16_t _vlanId, bool init_all) {
     ntop->getTrace()->traceEvent(TRACE_WARNING, "Internal error: NULL mutex. Are you running out of memory?");
 
   memset(&tcpPacketStats, 0, sizeof(tcpPacketStats));
-  memset(&ifa_stats, 0, sizeof(ifa_stats));
   asn = 0, asname = NULL, country = NULL, city = NULL;
   longitude = 0, latitude = 0, host_quota_mb = 0;
   k = get_string_key(key, sizeof(key));
   snprintf(redis_key, sizeof(redis_key), HOST_SERIALIZED_KEY, iface->get_id(), k, vlan_id);
-  dns = NULL, http = NULL, categoryStats = NULL, topSitesKey = NULL;
+  dns = NULL, http = NULL, categoryStats = NULL, topSitesKey = NULL,
+    user_activities = NULL, ifa_stats = NULL;
 
 #ifdef NTOPNG_PRO
   l7Policy = NULL;
 #endif
 
   if(init_all) {
-    if(ip) {
-      char sitesBuf[64], *strIP = ip->print(buf, sizeof(buf));
+    char sitesBuf[64], *strIP = ip.print(buf, sizeof(buf));
 
-      snprintf(host, sizeof(host), "%s@%u", strIP, vlan_id);
+    snprintf(host, sizeof(host), "%s@%u", strIP, vlan_id);
 
-      updateLocal();
-      updateHostTrafficPolicy(host);
-      systemHost = ip->isLocalInterfaceAddress();
+    updateLocal();
+    updateHostTrafficPolicy(host);
+    systemHost = ip.isLocalInterfaceAddress();
 
-      if(localHost) {
-	char oldk[64];
+    if(localHost) {
+      char oldk[64];
 
-	snprintf(sitesBuf, sizeof(sitesBuf), "sites.%s", strIP);
-	topSitesKey = strdup(sitesBuf);
+      snprintf(sitesBuf, sizeof(sitesBuf), "sites.%s", strIP);
+      topSitesKey = strdup(sitesBuf);
 
-	snprintf(oldk, sizeof(oldk), "%s.old", topSitesKey);
-	ntop->getRedis()->rename(topSitesKey, oldk);
-      }
-
-      // ntop->getTrace()->traceEvent(TRACE_NORMAL, "Loading %s (%s)", k, localHost ? "local": "remote");
-
-      if(localHost || systemHost) {
-	dns = new DnsStats();
-	http = new HTTPstats(iface->get_hosts_hash());
-      }
-
-      if((localHost || systemHost)
-	 && ntop->getPrefs()->is_idle_local_host_cache_enabled()){
-	char *json;
-	if((json = (char*)malloc(HOST_MAX_SERIALIZED_LEN * sizeof(char))) == NULL)
-	  ntop->getTrace()->traceEvent(TRACE_ERROR,
-				       "Unable to allocate memory to deserialize %s", redis_key);
-	else if(!ntop->getRedis()->get(redis_key, json, HOST_MAX_SERIALIZED_LEN)){
-	  /* Found saved copy of the host so let's start from the previous state */
-	  // ntop->getTrace()->traceEvent(TRACE_NORMAL, "%s => %s", redis_key, json);
-	  ntop->getTrace()->traceEvent(TRACE_INFO, "Deserializing %s", redis_key);
-	  deserialize(json, redis_key);
-	}
-	if(json) free(json);
-      }
-
-      if(localHost || systemHost
-	 || ntop->getPrefs()->is_dns_resolution_enabled_for_all_hosts()) {
-	char rsp[256];
-
-	if(ntop->getRedis()->getAddress(host, rsp, sizeof(rsp), true) == 0)
-	  setName(rsp);
-	// else ntop->getRedis()->pushHostToResolve(host, false, localHost);
-      }
-
-      if((!localHost || systemHost)
-	 && ntop->getPrefs()->is_httpbl_enabled()
-	 && ip->isIPv4()) {
-	// http:bl only works for IPv4 addresses
-	if(ntop->getRedis()->getAddressTrafficFiltering(host, iface, trafficCategory,
-							sizeof(trafficCategory), true) == 0) {
-          if(strcmp(trafficCategory, NULL_BL)) {
-	    blacklisted_host = true;
-	    ntop->getTrace()->traceEvent(TRACE_INFO,
-					 "Blacklisted host found %s [%s]",
-					 host, trafficCategory);
-	  }
-	}
-      }
-
-      if(asname) { free(asname); asname = NULL; }
-      ntop->getGeolocation()->getAS(ip, &asn, &asname);
-
-      if(country) { free(country); country = NULL; }
-      if(city)    { free(city); city = NULL;       }
-      ntop->getGeolocation()->getInfo(ip, &country, &city, &latitude, &longitude);
-    } else {
-      char buf[32];
-
-      snprintf(buf, sizeof(buf), "%02X:%02X:%02X:%02X:%02X:%02X",
-	       mac_address[0], mac_address[1], mac_address[2],
-	       mac_address[3], mac_address[4], mac_address[5]);
-
-      setName(buf);
-      localHost = true;
+      snprintf(oldk, sizeof(oldk), "%s.old", topSitesKey);
+      ntop->getRedis()->rename(topSitesKey, oldk);
     }
 
-    if((localHost || systemHost) && ip) {
+    // ntop->getTrace()->traceEvent(TRACE_NORMAL, "Loading %s (%s)", k, localHost ? "local": "remote");
+
+    if(localHost || systemHost) {
+      dns = new DnsStats();
+      http = new HTTPstats(iface->get_hosts_hash());
+    }
+
+    if((localHost || systemHost)
+       && ntop->getPrefs()->is_idle_local_host_cache_enabled()){
+      char *json;
+      if((json = (char*)malloc(HOST_MAX_SERIALIZED_LEN * sizeof(char))) == NULL)
+	ntop->getTrace()->traceEvent(TRACE_ERROR,
+				     "Unable to allocate memory to deserialize %s", redis_key);
+      else if(!ntop->getRedis()->get(redis_key, json, HOST_MAX_SERIALIZED_LEN)){
+	/* Found saved copy of the host so let's start from the previous state */
+	// ntop->getTrace()->traceEvent(TRACE_NORMAL, "%s => %s", redis_key, json);
+	ntop->getTrace()->traceEvent(TRACE_INFO, "Deserializing %s", redis_key);
+	deserialize(json, redis_key);
+      }
+      if(json) free(json);
+    }
+
+    if(localHost || systemHost
+       || ntop->getPrefs()->is_dns_resolution_enabled_for_all_hosts()) {
+      char rsp[256];
+
+      if(ntop->getRedis()->getAddress(host, rsp, sizeof(rsp), true) == 0)
+	setName(rsp);
+      // else ntop->getRedis()->pushHostToResolve(host, false, localHost);
+    }
+
+    if((!localHost || systemHost)
+       && ntop->getPrefs()->is_httpbl_enabled()
+       && ip.isIPv4()) {
+      // http:bl only works for IPv4 addresses
+      if(ntop->getRedis()->getAddressTrafficFiltering(host, iface, trafficCategory,
+						      sizeof(trafficCategory), true) == 0) {
+	if(strcmp(trafficCategory, NULL_BL)) {
+	  blacklisted_host = true;
+	  ntop->getTrace()->traceEvent(TRACE_INFO,
+				       "Blacklisted host found %s [%s]",
+				       host, trafficCategory);
+	}
+      }
+    }
+
+    if(asname) { free(asname); asname = NULL; }
+    ntop->getGeolocation()->getAS(&ip, &asn, &asname);
+
+    if(country) { free(country); country = NULL; }
+    if(city)    { free(city); city = NULL;       }
+    ntop->getGeolocation()->getInfo(&ip, &country, &city, &latitude, &longitude);
+    
+    if(localHost || systemHost) {
 #ifdef NTOPNG_PRO
       sent_to_sketch   = new CountMinSketch();
       rcvd_from_sketch = new CountMinSketch();
 #endif
       readStats();
+
+      if(ntop->getPrefs()->is_flow_activity_enabled()) {
+	ifa_stats = new InterFlowActivityStats[IFA_STATS_PROTOS_N*INTER_FLOW_ACTIVITY_SLOTS];
+	user_activities = new UserActivityStats;
+	
+	if(ifa_stats) memset(ifa_stats, 0, sizeof(InterFlowActivityStats)*IFA_STATS_PROTOS_N*INTER_FLOW_ACTIVITY_SLOTS);
+	if(user_activities) memset(user_activities, 0, sizeof(UserActivityStats));
+      }
     }
   }
 
@@ -266,16 +251,14 @@ void Host::updateHostTrafficPolicy(char *key) {
   if(localHost || systemHost) {
     char buf[64], *host, host_buf[96];
 
-    if(!ip) return;
-
     if(key)
       host = key;
     else {
       if(vlan_id > 0) {
-	snprintf(host_buf, sizeof(host_buf), "%s@%u", ip->print(buf, sizeof(buf)), vlan_id);
+	snprintf(host_buf, sizeof(host_buf), "%s@%u", ip.print(buf, sizeof(buf)), vlan_id);
 	host = host_buf;
       } else
-	host = ip->print(buf, sizeof(buf));
+	host = ip.print(buf, sizeof(buf));
     }
 
     if(iface->isPacketInterface()) {
@@ -305,14 +288,14 @@ void Host::updateHostL7Policy() {
   if(!iface->is_bridge_interface()) return;
 
   if(ntop->getPro()->has_valid_license()) {
-    if((localHost || systemHost) && ip) {
+    if(localHost || systemHost) {
       char host_key[64], hash_name[64], rsp[32];
       char buf[64], *host;
       u_int8_t bitmask;
 
-      l7Policy = getInterface()->getL7Policer()->getIpPolicy(ip, vlan_id, &bitmask);
+      l7Policy = getInterface()->getL7Policer()->getIpPolicy(&ip, vlan_id, &bitmask);
 
-      host = ip->print(buf, sizeof(buf), bitmask);
+      host = ip.print(buf, sizeof(buf), bitmask);
       snprintf(host_key, sizeof(host_key), "%s/%u@%u", host,
 	       bitmask, vlan_id);
 
@@ -371,8 +354,7 @@ bool Host::doDropProtocol(ndpi_protocol l7_proto) {
 /* *************************************** */
 
 void Host::updateLocal() {
-  if(ip)
-    localHost = ip->isLocalHost(&local_network_id);
+  localHost = ip.isLocalHost(&local_network_id);
 
   if(local_network_id >= 0)
     networkStats = getNetworkStats(local_network_id);
@@ -381,35 +363,30 @@ void Host::updateLocal() {
     char buf[64];
 
     ntop->getTrace()->traceEvent(TRACE_NORMAL, "%s is %s",
-				 ip->print(buf, sizeof(buf)), localHost ? "local" : "remote");
+				 ip.print(buf, sizeof(buf)), 
+				 localHost ? "local" : "remote");
   }
 }
 
 /* *************************************** */
 
-char* Host::get_mac(char *buf, u_int buf_len, u_int8_t *mac) {
-  snprintf(buf, buf_len,
-	   "%02X:%02X:%02X:%02X:%02X:%02X",
-	   mac[0] & 0xFF, mac[1] & 0xFF,
-	   mac[2] & 0xFF, mac[3] & 0xFF,
-	   mac[4] & 0xFF, mac[5] & 0xFF);
-
-  return(buf);
-}
-
-/* *************************************** */
-
 void Host::set_mac(char *m) {
-  u_int32_t mac[6] = { 0 };
+  u_int8_t mac_address[6];
+  u_int32_t _mac[6] = { 0 };
 
   if(!strcmp(m, "00:00:00:00:00:00")) return;
 
   sscanf(m, "%02X:%02X:%02X:%02X:%02X:%02X",
-	 &mac[0], &mac[1], &mac[2], &mac[3], &mac[4], &mac[5]);
+	 &_mac[0], &_mac[1], &_mac[2], &_mac[3], &_mac[4], &_mac[5]);
 
-  mac_address[0] = mac[0], mac_address[1] = mac[1],
-    mac_address[2] = mac[2], mac_address[3] = mac[3],
-    mac_address[4] = mac[4], mac_address[5] = mac[5];
+  mac_address[0] = _mac[0], mac_address[1] = _mac[1],
+    mac_address[2] = _mac[2], mac_address[3] = _mac[3],
+    mac_address[4] = _mac[4], mac_address[5] = _mac[5];
+
+  if(mac) mac->decUses();
+
+  if((mac = iface->getMac(mac_address, vlan_id, true)) != NULL)
+    mac->incUses();
 }
 
 /* *************************************** */
@@ -448,24 +425,18 @@ void Host::lua(lua_State* vm, patricia_tree_t *ptree,
 	       bool exclude_deserialized_bytes) {
   char buf[64];
   char buf_id[64];
+  char ip_buf[64];
   char *ipaddr = NULL;
+  char *local_net;
 
   if(ptree && (!match(ptree)))
     return;
 
   lua_newtable(vm);
+  lua_push_str_table_entry(vm, "ip", (ipaddr = ip.print(ip_buf, sizeof(ip_buf))));
+  lua_push_int_table_entry(vm, "ipkey", ip.key());
 
-  if(ip) {
-    char ip_buf[64];
-
-    lua_push_str_table_entry(vm, "ip", (ipaddr = ip->print(ip_buf, sizeof(ip_buf))));
-    lua_push_int_table_entry(vm, "ipkey", ip->key());
-  } else {
-    lua_push_nil_table_entry(vm, "ip");
-    lua_push_nil_table_entry(vm, "ipkey");
-  }
-
-  lua_push_str_table_entry(vm, "mac", get_mac(buf, sizeof(buf), mac_address));
+  lua_push_str_table_entry(vm, "mac", Utils::formatMac(mac ? mac->get_mac() : NULL, buf, sizeof(buf)));
   lua_push_int_table_entry(vm, "vlan", vlan_id);
   lua_push_bool_table_entry(vm, "localhost", localHost);
 
@@ -474,191 +445,178 @@ void Host::lua(lua_State* vm, patricia_tree_t *ptree,
   lua_push_int_table_entry(vm, "bytes.rcvd",
 			   rcvd.getNumBytes() - (exclude_deserialized_bytes ? rcvd.getNumDeserializedBytes() : 0));
 
-  if(ip) {
-    char *local_net;
+  lua_push_bool_table_entry(vm, "privatehost", isPrivateHost());
 
-    lua_push_bool_table_entry(vm, "privatehost", isPrivateHost());
+  if(host_details) {
+    /*
+      This has been disabled as in case of an attack, most hosts do not have a name and we will waste
+      a lot of time doing activities that are not necessary
+    */
+    if((symbolic_name == NULL) || (strcmp(symbolic_name, ipaddr) == 0)) {
+      /* We resolve immediately the IP address by queueing on the top of address queue */
 
-    if(host_details) {
-      /*
-	This has been disabled as in case of an attack, most hosts do not have a name and we will waste
-	a lot of time doing activities that are not necessary
-      */
-      if((symbolic_name == NULL) || (strcmp(symbolic_name, ipaddr) == 0)) {
-	/* We resolve immediately the IP address by queueing on the top of address queue */
-
-	ntop->getRedis()->pushHostToResolve(ipaddr, false, true /* Fake to resolve it ASAP */);
-      }
-    }
-
-    lua_push_str_table_entry(vm, "name",
-			     get_name(buf, sizeof(buf), false));
-    lua_push_int32_table_entry(vm, "local_network_id", local_network_id);
-
-    local_net = ntop->getLocalNetworkName(local_network_id);
-    if(local_net == NULL)
-      lua_push_nil_table_entry(vm, "local_network_name");
-    else
-      lua_push_str_table_entry(vm, "local_network_name", local_net);
-
-    lua_push_bool_table_entry(vm, "systemhost", systemHost);
-    lua_push_int_table_entry(vm, "source_id", source_id);
-    lua_push_int_table_entry(vm, "asn", ip ? asn : 0);
-
-    lua_push_str_table_entry(vm, "asname", ip ? asname : (char*)"");
-    lua_push_str_table_entry(vm, "os", os);
-
-    lua_push_str_table_entry(vm, "country", country ? country : (char*)"");
-    lua_push_int_table_entry(vm, "active_flows.as_client", num_active_flows_as_client);
-    lua_push_int_table_entry(vm, "active_flows.as_server", num_active_flows_as_server);
-    lua_push_int_table_entry(vm, "active_http_hosts", http ? http->get_num_virtual_hosts() : 0);
-
-    if(host_details) {
-      lua_push_str_table_entry(vm, "deviceIP", Utils::intoaV4(deviceIP, buf, sizeof(buf)));
-      lua_push_int_table_entry(vm, "deviceIfIdx", deviceIfIdx);
-      lua_push_float_table_entry(vm, "latitude", latitude);
-      lua_push_float_table_entry(vm, "longitude", longitude);
-      lua_push_str_table_entry(vm, "city", city ? city : (char*)"");
-      lua_push_int_table_entry(vm, "packets.sent", sent.getNumPkts());
-      lua_push_int_table_entry(vm, "packets.rcvd", rcvd.getNumPkts());
-      lua_push_int_table_entry(vm, "flows.as_client", total_num_flows_as_client);
-      lua_push_int_table_entry(vm, "flows.as_server", total_num_flows_as_server);
-      lua_push_int_table_entry(vm, "udp.packets.sent",  udp_sent.getNumPkts());
-      lua_push_int_table_entry(vm, "udp.bytes.sent", udp_sent.getNumBytes());
-      lua_push_int_table_entry(vm, "udp.packets.rcvd",  udp_rcvd.getNumPkts());
-      lua_push_int_table_entry(vm, "udp.bytes.rcvd", udp_rcvd.getNumBytes());
-
-      lua_push_int_table_entry(vm, "tcp.packets.sent",  tcp_sent.getNumPkts());
-
-      lua_push_bool_table_entry(vm, "tcp.packets.seq_problems",
-				(tcpPacketStats.pktRetr
-				 || tcpPacketStats.pktOOO
-				 || tcpPacketStats.pktLost) ? true : false);
-      lua_push_int_table_entry(vm, "tcp.packets.retransmissions", tcpPacketStats.pktRetr);
-      lua_push_int_table_entry(vm, "tcp.packets.out_of_order", tcpPacketStats.pktOOO);
-      lua_push_int_table_entry(vm, "tcp.packets.lost", tcpPacketStats.pktLost);
-
-      lua_push_int_table_entry(vm, "tcp.bytes.sent", tcp_sent.getNumBytes());
-      lua_push_int_table_entry(vm, "tcp.packets.rcvd",  tcp_rcvd.getNumPkts());
-      lua_push_int_table_entry(vm, "tcp.bytes.rcvd", tcp_rcvd.getNumBytes());
-
-      lua_push_int_table_entry(vm, "icmp.packets.sent",  icmp_sent.getNumPkts());
-      lua_push_int_table_entry(vm, "icmp.bytes.sent", icmp_sent.getNumBytes());
-      lua_push_int_table_entry(vm, "icmp.packets.rcvd",  icmp_rcvd.getNumPkts());
-      lua_push_int_table_entry(vm, "icmp.bytes.rcvd", icmp_rcvd.getNumBytes());
-
-      lua_push_int_table_entry(vm, "other_ip.packets.sent",  other_ip_sent.getNumPkts());
-      lua_push_int_table_entry(vm, "other_ip.bytes.sent", other_ip_sent.getNumBytes());
-      lua_push_int_table_entry(vm, "other_ip.packets.rcvd",  other_ip_rcvd.getNumPkts());
-      lua_push_int_table_entry(vm, "other_ip.bytes.rcvd", other_ip_rcvd.getNumBytes());
-
-      lua_push_bool_table_entry(vm, "drop_all_host_traffic", drop_all_host_traffic);
-
-      /* Host ingress/egress drops */
-      lua_push_int_table_entry(vm, "bridge.ingress_drops.bytes", ingress_drops.getNumBytes());
-      lua_push_int_table_entry(vm, "bridge.ingress_drops.packets",  ingress_drops.getNumPkts());
-      lua_push_int_table_entry(vm, "bridge.egress_drops.bytes", egress_drops.getNumBytes());
-      lua_push_int_table_entry(vm, "bridge.egress_drops.packets",  egress_drops.getNumPkts());
-
-      lua_push_int_table_entry(vm, "host_quota_mb", host_quota_mb);
-
-      if(localHost || systemHost) {
-	lua_push_int_table_entry(vm, "bridge.ingress_shaper_id", ingress_shaper_id);
-	lua_push_int_table_entry(vm, "bridge.egress_shaper_id", egress_shaper_id);
-	lua_push_int_table_entry(vm, "bridge.host_quota_mb", host_quota_mb);
-      }
-
-      lua_push_int_table_entry(vm, "low_goodput_flows.as_client", low_goodput_client_flows);
-      lua_push_int_table_entry(vm, "low_goodput_flows.as_server", low_goodput_server_flows);
-
-
-      if(topSitesKey) {
-	char oldk[64];
-
-	snprintf(oldk, sizeof(oldk), "%s.old", topSitesKey);
-
-	getSites(vm, topSitesKey, "sites");
-	getSites(vm, oldk, "sites.old");
-      }
-    }
-
-    lua_push_int_table_entry(vm, "seen.first", first_seen);
-    lua_push_int_table_entry(vm, "seen.last", last_seen);
-    lua_push_int_table_entry(vm, "duration", get_duration());
-
-    lua_push_float_table_entry(vm, "throughput_bps", bytes_thpt);
-    lua_push_float_table_entry(vm, "last_throughput_bps", last_bytes_thpt);
-    lua_push_int_table_entry(vm, "throughput_trend_bps", bytes_thpt_trend);
-    lua_push_float_table_entry(vm, "throughput_trend_bps_diff", bytes_thpt_diff);
-
-    // ntop->getTrace()->traceEvent(TRACE_NORMAL, "[bytes_thpt: %.2f] [bytes_thpt_trend: %d]", bytes_thpt,bytes_thpt_trend);
-    lua_push_float_table_entry(vm, "throughput_pps", pkts_thpt);
-    lua_push_float_table_entry(vm, "last_throughput_pps", last_pkts_thpt);
-    lua_push_int_table_entry(vm, "throughput_trend_pps", pkts_thpt_trend);
-
-    // ntop->getTrace()->traceEvent(TRACE_NORMAL, "[pkts_thpt: %.2f] [pkts_thpt_trend: %d]", pkts_thpt,pkts_thpt_trend);
-    lua_push_int_table_entry(vm, "num_alerts", triggerAlerts() ? getNumAlerts() : 0);
-
-    if(ip) {
-      if(ntop->getPrefs()->is_httpbl_enabled())
-	lua_push_str_table_entry(vm, "httpbl", get_httpbl());
-    }
-
-    lua_push_bool_table_entry(vm, "dump_host_traffic", dump_host_traffic);
-
-    if(verbose) {
-      char *rsp = serialize();
-
-      if(categoryStats) categoryStats->lua(vm);
-      if(ndpiStats) ndpiStats->lua(iface, vm);
-      lua_push_str_table_entry(vm, "json", rsp);
-      free(rsp);
-
-      sent_stats.lua(vm, "pktStats.sent");
-      recv_stats.lua(vm, "pktStats.recv");
-
-      if(dns)  dns->lua(vm);
-      if(http) http->lua(vm);
-
-#ifdef NTOPNG_PRO
-      if(ntop->getPro()->has_valid_license()) {
-	if(l7Policy != NULL) {
-	  lua_newtable(vm);
-
-	  for(int i=1; i<NDPI_MAX_SUPPORTED_PROTOCOLS+NDPI_MAX_NUM_CUSTOM_PROTOCOLS; i++) {
-	    if(NDPI_ISSET(l7Policy, i)) {
-	      char *proto = ndpi_get_proto_by_id(iface->get_ndpi_struct(), i);
-
-	      if(proto)
-		lua_push_int_table_entry(vm, proto, i);
-	    }
-	  }
-
-	  lua_pushstring(vm, "l7_traffic_policy");
-	  lua_insert(vm, -2);
-	  lua_settable(vm, -3);
-	}
-      }
-#endif
-    }
-
-    if(!returnHost) {
-      /* Use the ip@vlan_id as a key only in case of multi vlan_id, otherwise use only the ip as a key */
-      if(vlan_id == 0) {
-        sprintf(buf_id, "%s",(ip != NULL) ? ip->print(buf, sizeof(buf)) : get_mac(buf, sizeof(buf), mac_address));
-      } else {
-        sprintf(buf_id, "%s@%d",(ip != NULL) ? ip->print(buf, sizeof(buf)) : get_mac(buf, sizeof(buf), mac_address), vlan_id );
-      }
-    }
-  } else {
-    /* Use the ip@vlan_id as a key only in case of multi vlan_id, otherwise use only the ip as a key */
-    if(vlan_id == 0) {
-      sprintf(buf_id, "%s",(ip != NULL) ? ip->print(buf, sizeof(buf)) : get_mac(buf, sizeof(buf), mac_address));
-    } else {
-      sprintf(buf_id, "%s@%d",(ip != NULL) ? ip->print(buf, sizeof(buf)) : get_mac(buf, sizeof(buf), mac_address),vlan_id );
+      ntop->getRedis()->pushHostToResolve(ipaddr, false, true /* Fake to resolve it ASAP */);
     }
   }
 
+  lua_push_str_table_entry(vm, "name",
+			   get_name(buf, sizeof(buf), false));
+  lua_push_int32_table_entry(vm, "local_network_id", local_network_id);
+
+  local_net = ntop->getLocalNetworkName(local_network_id);
+  if(local_net == NULL)
+    lua_push_nil_table_entry(vm, "local_network_name");
+  else
+    lua_push_str_table_entry(vm, "local_network_name", local_net);
+
+  lua_push_bool_table_entry(vm, "systemhost", systemHost);
+  lua_push_int_table_entry(vm, "source_id", source_id);
+  lua_push_int_table_entry(vm, "asn", asn);
+
+  lua_push_str_table_entry(vm, "asname", asname);
+  lua_push_str_table_entry(vm, "os", os);
+
+  lua_push_str_table_entry(vm, "country", country ? country : (char*)"");
+  lua_push_int_table_entry(vm, "active_flows.as_client", num_active_flows_as_client);
+  lua_push_int_table_entry(vm, "active_flows.as_server", num_active_flows_as_server);
+  lua_push_int_table_entry(vm, "active_http_hosts", http ? http->get_num_virtual_hosts() : 0);
+
+  if(host_details) {
+    lua_push_str_table_entry(vm, "deviceIP", Utils::intoaV4(deviceIP, buf, sizeof(buf)));
+    lua_push_int_table_entry(vm, "deviceIfIdx", deviceIfIdx);
+    lua_push_float_table_entry(vm, "latitude", latitude);
+    lua_push_float_table_entry(vm, "longitude", longitude);
+    lua_push_str_table_entry(vm, "city", city ? city : (char*)"");
+    lua_push_int_table_entry(vm, "packets.sent", sent.getNumPkts());
+    lua_push_int_table_entry(vm, "packets.rcvd", rcvd.getNumPkts());
+    lua_push_int_table_entry(vm, "flows.as_client", total_num_flows_as_client);
+    lua_push_int_table_entry(vm, "flows.as_server", total_num_flows_as_server);
+    lua_push_int_table_entry(vm, "udp.packets.sent",  udp_sent.getNumPkts());
+    lua_push_int_table_entry(vm, "udp.bytes.sent", udp_sent.getNumBytes());
+    lua_push_int_table_entry(vm, "udp.packets.rcvd",  udp_rcvd.getNumPkts());
+    lua_push_int_table_entry(vm, "udp.bytes.rcvd", udp_rcvd.getNumBytes());
+
+    lua_push_int_table_entry(vm, "tcp.packets.sent",  tcp_sent.getNumPkts());
+
+    lua_push_bool_table_entry(vm, "tcp.packets.seq_problems",
+			      (tcpPacketStats.pktRetr
+			       || tcpPacketStats.pktOOO
+			       || tcpPacketStats.pktLost) ? true : false);
+    lua_push_int_table_entry(vm, "tcp.packets.retransmissions", tcpPacketStats.pktRetr);
+    lua_push_int_table_entry(vm, "tcp.packets.out_of_order", tcpPacketStats.pktOOO);
+    lua_push_int_table_entry(vm, "tcp.packets.lost", tcpPacketStats.pktLost);
+
+    lua_push_int_table_entry(vm, "tcp.bytes.sent", tcp_sent.getNumBytes());
+    lua_push_int_table_entry(vm, "tcp.packets.rcvd",  tcp_rcvd.getNumPkts());
+    lua_push_int_table_entry(vm, "tcp.bytes.rcvd", tcp_rcvd.getNumBytes());
+
+    lua_push_int_table_entry(vm, "icmp.packets.sent",  icmp_sent.getNumPkts());
+    lua_push_int_table_entry(vm, "icmp.bytes.sent", icmp_sent.getNumBytes());
+    lua_push_int_table_entry(vm, "icmp.packets.rcvd",  icmp_rcvd.getNumPkts());
+    lua_push_int_table_entry(vm, "icmp.bytes.rcvd", icmp_rcvd.getNumBytes());
+
+    lua_push_int_table_entry(vm, "other_ip.packets.sent",  other_ip_sent.getNumPkts());
+    lua_push_int_table_entry(vm, "other_ip.bytes.sent", other_ip_sent.getNumBytes());
+    lua_push_int_table_entry(vm, "other_ip.packets.rcvd",  other_ip_rcvd.getNumPkts());
+    lua_push_int_table_entry(vm, "other_ip.bytes.rcvd", other_ip_rcvd.getNumBytes());
+
+    lua_push_bool_table_entry(vm, "drop_all_host_traffic", drop_all_host_traffic);
+
+    /* Host ingress/egress drops */
+    lua_push_int_table_entry(vm, "bridge.ingress_drops.bytes", ingress_drops.getNumBytes());
+    lua_push_int_table_entry(vm, "bridge.ingress_drops.packets",  ingress_drops.getNumPkts());
+    lua_push_int_table_entry(vm, "bridge.egress_drops.bytes", egress_drops.getNumBytes());
+    lua_push_int_table_entry(vm, "bridge.egress_drops.packets",  egress_drops.getNumPkts());
+
+    lua_push_int_table_entry(vm, "host_quota_mb", host_quota_mb);
+
+    if(localHost || systemHost) {
+      lua_push_int_table_entry(vm, "bridge.ingress_shaper_id", ingress_shaper_id);
+      lua_push_int_table_entry(vm, "bridge.egress_shaper_id", egress_shaper_id);
+      lua_push_int_table_entry(vm, "bridge.host_quota_mb", host_quota_mb);
+    }
+
+    lua_push_int_table_entry(vm, "low_goodput_flows.as_client", low_goodput_client_flows);
+    lua_push_int_table_entry(vm, "low_goodput_flows.as_server", low_goodput_server_flows);
+
+
+    if(topSitesKey) {
+      char oldk[64];
+
+      snprintf(oldk, sizeof(oldk), "%s.old", topSitesKey);
+
+      getSites(vm, topSitesKey, "sites");
+      getSites(vm, oldk, "sites.old");
+    }
+  }
+
+  lua_push_int_table_entry(vm, "seen.first", first_seen);
+  lua_push_int_table_entry(vm, "seen.last", last_seen);
+  lua_push_int_table_entry(vm, "duration", get_duration());
+
+  lua_push_float_table_entry(vm, "throughput_bps", bytes_thpt);
+  lua_push_float_table_entry(vm, "last_throughput_bps", last_bytes_thpt);
+  lua_push_int_table_entry(vm, "throughput_trend_bps", bytes_thpt_trend);
+  lua_push_float_table_entry(vm, "throughput_trend_bps_diff", bytes_thpt_diff);
+
+  // ntop->getTrace()->traceEvent(TRACE_NORMAL, "[bytes_thpt: %.2f] [bytes_thpt_trend: %d]", bytes_thpt,bytes_thpt_trend);
+  lua_push_float_table_entry(vm, "throughput_pps", pkts_thpt);
+  lua_push_float_table_entry(vm, "last_throughput_pps", last_pkts_thpt);
+  lua_push_int_table_entry(vm, "throughput_trend_pps", pkts_thpt_trend);
+
+  // ntop->getTrace()->traceEvent(TRACE_NORMAL, "[pkts_thpt: %.2f] [pkts_thpt_trend: %d]", pkts_thpt,pkts_thpt_trend);
+  lua_push_int_table_entry(vm, "num_alerts", triggerAlerts() ? getNumAlerts() : 0);
+
+  if(ntop->getPrefs()->is_httpbl_enabled())
+    lua_push_str_table_entry(vm, "httpbl", get_httpbl());
+
+  lua_push_bool_table_entry(vm, "dump_host_traffic", dump_host_traffic);
+
+  if(verbose) {
+    char *rsp = serialize();
+
+    if(categoryStats) categoryStats->lua(vm);
+    if(ndpiStats) ndpiStats->lua(iface, vm);
+    lua_push_str_table_entry(vm, "json", rsp);
+    free(rsp);
+
+    sent_stats.lua(vm, "pktStats.sent");
+    recv_stats.lua(vm, "pktStats.recv");
+
+    if(dns)  dns->lua(vm);
+    if(http) http->lua(vm);
+
+#ifdef NTOPNG_PRO
+    if(ntop->getPro()->has_valid_license()) {
+      if(l7Policy != NULL) {
+	lua_newtable(vm);
+
+	for(int i=1; i<NDPI_MAX_SUPPORTED_PROTOCOLS+NDPI_MAX_NUM_CUSTOM_PROTOCOLS; i++) {
+	  if(NDPI_ISSET(l7Policy, i)) {
+	    char *proto = ndpi_get_proto_by_id(iface->get_ndpi_struct(), i);
+
+	    if(proto)
+	      lua_push_int_table_entry(vm, proto, i);
+	  }
+	}
+
+	lua_pushstring(vm, "l7_traffic_policy");
+	lua_insert(vm, -2);
+	lua_settable(vm, -3);
+      }
+    }
+#endif
+  }
+
+  if(!returnHost) {
+    /* Use the ip@vlan_id as a key only in case of multi vlan_id, otherwise use only the ip as a key */
+    if(vlan_id == 0) {
+      sprintf(buf_id, "%s", ip.print(buf, sizeof(buf)));
+    } else {
+      sprintf(buf_id, "%s@%d", ip.print(buf, sizeof(buf)), vlan_id);
+    }
+  }  
+
   if(asListElement) {
     lua_pushstring(vm, buf_id);
     lua_insert(vm, -2);
@@ -685,13 +643,12 @@ void Host::setName(char *name) {
 /* ***************************************** */
 
 void Host::refreshHTTPBL() {
-  if(ip
-     && ip->isIPv4()
+  if(ip.isIPv4()
      && (!localHost)
      && (trafficCategory[0] == '\0')
      && ntop->get_httpbl()) {
     char buf[128] =  { 0 };
-    char* ip_addr = ip->print(buf, sizeof(buf));
+    char* ip_addr = ip.print(buf, sizeof(buf));
 
     ntop->get_httpbl()->findCategory(ip_addr, trafficCategory, sizeof(trafficCategory), false);
   }
@@ -700,51 +657,37 @@ void Host::refreshHTTPBL() {
 /* ***************************************** */
 
 char* Host::get_name(char *buf, u_int buf_len, bool force_resolution_if_not_found) {
-  if(ip == NULL) {
-    return(get_mac(buf, buf_len, mac_address));
-  } else {
-    char *addr, redis_buf[64];
-    int rc;
-    time_t now = time(NULL);
-
-    if(nextResolveAttempt
-       && ((nextResolveAttempt > now) || (nextResolveAttempt == (time_t)-1))) {
-      return(symbolic_name);
-    } else
-      nextResolveAttempt = ntop->getPrefs()->is_dns_resolution_enabled() ? now + MIN_HOST_RESOLUTION_FREQUENCY : (time_t)-1;
-
-    addr = ip->print(buf, buf_len);
-
-    if((symbolic_name != NULL) && strcmp(symbolic_name, addr))
-      return(symbolic_name);
-
-    rc = ntop->getRedis()->getAddress(addr, redis_buf, sizeof(redis_buf),
-				      force_resolution_if_not_found);
-
-    if(rc == 0)
-      setName(redis_buf);
-    else
-      setName(addr);
+  char *addr, redis_buf[64];
+  int rc;
+  time_t now = time(NULL);
 
+  if(nextResolveAttempt
+     && ((nextResolveAttempt > now) || (nextResolveAttempt == (time_t)-1))) {
     return(symbolic_name);
-  }
-}
+  } else
+    nextResolveAttempt = ntop->getPrefs()->is_dns_resolution_enabled() ? now + MIN_HOST_RESOLUTION_FREQUENCY : (time_t)-1;
 
-/* *************************************** */
+  addr = ip.print(buf, buf_len);
 
-int Host::compare(Host *h) {
-  if(ip)
-    return(ip->compare(h->ip));
+  if((symbolic_name != NULL) && strcmp(symbolic_name, addr))
+    return(symbolic_name);
+
+  rc = ntop->getRedis()->getAddress(addr, redis_buf, sizeof(redis_buf),
+				    force_resolution_if_not_found);
+
+  if(rc == 0)
+    setName(redis_buf);
   else
-    return(memcmp(mac_address, h->mac_address, 6));
+    setName(addr);
+
+  return(symbolic_name);  
 }
 
 /* ***************************************** */
 
 bool Host::idle() {
-  if(num_uses > 0) return(false);
-
-  if(!iface->is_purge_idle_interface()) return(false);
+  if((num_uses > 0) || (!iface->is_purge_idle_interface()))
+    return(false);
 
   switch(ntop->getPrefs()->get_host_stickness()) {
   case location_none:
@@ -766,20 +709,6 @@ bool Host::idle() {
   return(isIdle(ntop->getPrefs()->get_host_max_idle(localHost)));
 };
 
-/* ***************************************** */
-
-u_int32_t Host::key() {
-  if(ip)
-    return(ip->key());
-  else {
-    u_int32_t hash = 0;
-
-    for(int i=0; i<6; i++) hash += mac_address[i] << (i+1);
-
-    return(hash);
-  }
-}
-
 /* *************************************** */
 
 void Host::incStats(u_int8_t l4_proto, u_int ndpi_proto,
@@ -834,15 +763,6 @@ void Host::incStats(u_int8_t l4_proto, u_int ndpi_proto,
 
 /* *************************************** */
 
-char* Host::get_string_key(char *buf, u_int buf_len) {
-  if(ip != NULL)
-    return(ip->print(buf, buf_len));
-  else
-    return(get_mac(buf, buf_len, mac_address));
-}
-
-/* *************************************** */
-
 char* Host::serialize() {
   json_object *my_object = getJSONObject();
   char *rsp = strdup(json_object_to_json_string(my_object));
@@ -858,7 +778,7 @@ void Host::serialize2redis() {
   if((localHost || systemHost)
      && (ntop->getPrefs()->is_idle_local_host_cache_enabled()
 	 || ntop->getPrefs()->is_active_local_host_cache_enabled())
-     && ip && !ip->isEmpty()) {
+     && (!ip.isEmpty())) {
     char *json = serialize();
     char host_key[128], key[128];
     char *k = get_string_key(host_key, sizeof(host_key));
@@ -879,7 +799,7 @@ json_object* Host::getJSONObject() {
 
   if((my_object = json_object_new_object()) == NULL) return(NULL);
 
-  json_object_object_add(my_object, "mac_address", json_object_new_string(get_mac(buf, sizeof(buf), mac_address)));
+  json_object_object_add(my_object, "mac_address", json_object_new_string(Utils::formatMac(mac ? mac->get_mac() : NULL, buf, sizeof(buf))));
   json_object_object_add(my_object, "seen.first", json_object_new_int64(first_seen));
   json_object_object_add(my_object, "seen.last",  json_object_new_int64(last_seen));
   json_object_object_add(my_object, "asn", json_object_new_int(asn));
@@ -892,7 +812,7 @@ json_object* Host::getJSONObject() {
   if(vlan_id != 0)        json_object_object_add(my_object, "vlan_id",   json_object_new_int(vlan_id));
   if(latitude)            json_object_object_add(my_object, "latitude",  json_object_new_double(latitude));
   if(longitude)           json_object_object_add(my_object, "longitude", json_object_new_double(longitude));
-  if(ip)                  json_object_object_add(my_object, "ip", ip->getJSONObject());
+  json_object_object_add(my_object, "ip", ip.getJSONObject());
   if(deviceIfIdx)         json_object_object_add(my_object, "device_if_idx", json_object_new_int(deviceIfIdx));
   if(deviceIP)            json_object_object_add(my_object, "device_ip",     json_object_new_int(deviceIP));
   json_object_object_add(my_object, "localHost", json_object_new_boolean(localHost));
@@ -931,8 +851,8 @@ json_object* Host::getJSONObject() {
   json_object_object_add(my_object, "throughput_trend_pps", json_object_new_string(Utils::trend2str(pkts_thpt_trend)));
   json_object_object_add(my_object, "flows.as_client", json_object_new_int(total_num_flows_as_client));
   json_object_object_add(my_object, "flows.as_server", json_object_new_int(total_num_flows_as_server));
-  if (ntop->getPrefs()->is_flow_activity_enabled())
-    json_object_object_add(my_object, "userActivities", user_activities.getJSONObject());
+  if(user_activities)
+    json_object_object_add(my_object, "userActivities", user_activities->getJSONObject());
 
   /* Generic Host */
   json_object_object_add(my_object, "num_alerts", json_object_new_int(getNumAlerts()));
@@ -957,12 +877,12 @@ bool Host::addIfMatching(lua_State* vm, patricia_tree_t *ptree, char *key) {
 
   if(!match(ptree)) return(false);
 
-  // if(symbolic_name) ntop->getTrace()->traceEvent(TRACE_WARNING, "%s/%s", symbolic_name, ip->print(keybuf, sizeof(keybuf)));
+  // if(symbolic_name) ntop->getTrace()->traceEvent(TRACE_WARNING, "%s/%s", symbolic_name, ip.print(keybuf, sizeof(keybuf)));
 
-  if(strcasestr((r = get_mac(keybuf, sizeof(keybuf), mac_address)), key)) {
+  if(strcasestr((r = Utils::formatMac(mac ? mac->get_mac() : NULL, keybuf, sizeof(keybuf))), key)) {
     lua_push_str_table_entry(vm, get_string_key(keybuf, sizeof(keybuf)), r);
     return(true);
-  } else if(ip && strcasestr((r = ip->print(keybuf, sizeof(keybuf))), key)) {
+  } else if(strcasestr((r = ip.print(keybuf, sizeof(keybuf))), key)) {
     if(vlan_id != 0) {
       char valuebuf[96];
 
@@ -1012,7 +932,7 @@ bool Host::deserialize(char *json_str, char *key) {
   if(json_object_object_get_ex(o, "device_ip", &obj))     deviceIP    = json_object_get_int(obj);
   if(json_object_object_get_ex(o, "latitude", &obj))  latitude  = (float)json_object_get_double(obj);
   if(json_object_object_get_ex(o, "longitude", &obj)) longitude = (float)json_object_get_double(obj);
-  if(json_object_object_get_ex(o, "ip", &obj))  { if(ip == NULL) ip = new IpAddress(); if(ip) ip->deserialize(obj); }
+  if(json_object_object_get_ex(o, "ip", &obj))  { ip.deserialize(obj); }
   if(json_object_object_get_ex(o, "localHost", &obj)) localHost = (json_object_get_boolean(obj) ? true : false);
   if(json_object_object_get_ex(o, "systemHost", &obj)) systemHost = (json_object_get_boolean(obj) ? true : false);
   if(json_object_object_get_ex(o, "tcp_sent", &obj))  tcp_sent.deserialize(obj);
@@ -1035,7 +955,7 @@ bool Host::deserialize(char *json_str, char *key) {
   
   if(json_object_object_get_ex(o, "flows.as_client", &obj))  total_num_flows_as_client = json_object_get_int(obj);
   if(json_object_object_get_ex(o, "flows.as_server", &obj))  total_num_flows_as_server = json_object_get_int(obj);
-  if(json_object_object_get_ex(o, "userActivities", &obj))  user_activities.deserialize(obj);
+  if(user_activities) if(json_object_object_get_ex(o, "userActivities", &obj))  user_activities->deserialize(obj);
 
   if(json_object_object_get_ex(o, "flow_flood_attacker_alert", &obj)) flow_flood_attacker_alert = json_object_get_boolean(obj);
   if(json_object_object_get_ex(o, "flow_flood_victim_alert", &obj))   flow_flood_victim_alert   = json_object_get_boolean(obj);
@@ -1117,7 +1037,7 @@ void Host::updateSynFlags(time_t when, u_int8_t flags, Flow *f, bool syn_sent) {
     if(ntop->getUptime() < 10 /* sec */) return;
 #endif
 
-    h = ip->print(ip_buf, sizeof(ip_buf));
+    h = ip.print(ip_buf, sizeof(ip_buf));
 
     if(syn_sent) {
       error_msg = "Host <A HREF=%s/lua/host_details.lua?host=%s&ifname=%s>%s</A> is a SYN flooder [%u SYNs sent in the last %u sec] %s";
@@ -1160,7 +1080,7 @@ void Host::incNumFlows(bool as_client) {
       const char* error_msg = "Host <A HREF=%s/lua/host_details.lua?host=%s&ifname=%s>%s</A> is a possible scanner [%u active flows exceeded]";
       char ip_buf[48], *h, msg[512];
 
-      h = ip->print(ip_buf, sizeof(ip_buf));
+      h = ip.print(ip_buf, sizeof(ip_buf));
 
       snprintf(msg, sizeof(msg),
 	       error_msg, ntop->getPrefs()->get_http_prefix(),
@@ -1180,7 +1100,7 @@ void Host::incNumFlows(bool as_client) {
       const char* error_msg = "Host <A HREF=%s/lua/host_details.lua?host=%s&ifname=%s>%s</A> is possibly under scan attack [%u active flows exceeded]";
       char ip_buf[48], *h, msg[512];
 
-      h = ip->print(ip_buf, sizeof(ip_buf));
+      h = ip.print(ip_buf, sizeof(ip_buf));
 
       snprintf(msg, sizeof(msg),
 	       error_msg, ntop->getPrefs()->get_http_prefix(),
@@ -1207,7 +1127,7 @@ void Host::decNumFlows(bool as_client) {
 	const char* error_msg = "Host <A HREF=%s/lua/host_details.lua?host=%s&ifname=%s>%s</A> is no longer a possible scanner [less than %u active flows]";
 	char ip_buf[48], *h, msg[512];
 
-	h = ip->print(ip_buf, sizeof(ip_buf));
+	h = ip.print(ip_buf, sizeof(ip_buf));
 
 	snprintf(msg, sizeof(msg),
 		 error_msg, ntop->getPrefs()->get_http_prefix(),
@@ -1230,7 +1150,7 @@ void Host::decNumFlows(bool as_client) {
 	const char* error_msg = "Host <A HREF=%s/lua/host_details.lua?host=%s&ifname=%s>%s</A> is no longer under scan attack [less than %u active flows]";
 	char ip_buf[48], *h, msg[512];
 
-	h = ip->print(ip_buf, sizeof(ip_buf));
+	h = ip.print(ip_buf, sizeof(ip_buf));
 
 	snprintf(msg, sizeof(msg),
 		 error_msg, ntop->getPrefs()->get_http_prefix(),
@@ -1253,7 +1173,7 @@ void Host::decNumFlows(bool as_client) {
 void Host::setQuota(u_int32_t new_quota) {
   char buf[64], host[96];
 
-  snprintf(host, sizeof(host), "%s@%u", ip->print(buf, sizeof(buf)), vlan_id);
+  snprintf(host, sizeof(host), "%s@%u", ip.print(buf, sizeof(buf)), vlan_id);
   snprintf(buf, sizeof(buf), "%u", new_quota);
   if(ntop->getRedis()->hashSet((char*)HOST_TRAFFIC_QUOTA, host, (char *)buf) == -1) {
     ntop->getTrace()->traceEvent(TRACE_WARNING, "Error updating host quota");
@@ -1293,7 +1213,7 @@ void Host::updateStats(struct timeval *tv) {
   if(isAboveQuota()) {
     const char *error_msg = "Host <A HREF=%s/lua/host_details.lua?host=%s&ifname=%s>%s</A> is above quota [%u])";
     char ip_buf[48], *h, msg[512];
-    h = ip->print(ip_buf, sizeof(ip_buf));
+    h = ip.print(ip_buf, sizeof(ip_buf));
 
     snprintf(msg, sizeof(msg),
              error_msg, ntop->getPrefs()->get_http_prefix(),
@@ -1310,50 +1230,47 @@ void Host::loadAlertPrefs() {
   loadFlowsAlertPrefs();
 }
 
+/* *************************************** */
+
 void Host::loadFlowRateAlertPrefs() {
   int retval = CONST_MAX_NEW_FLOWS_SECOND;
-
-  if(ip != NULL) {
-    char rkey[128], rsp[16];
-    char ip_buf[48];
-
-    snprintf(rkey, sizeof(rkey), "ntopng.prefs.%s:%d.flow_rate_alert_threshold",
-             ip->print(ip_buf, sizeof(ip_buf)), vlan_id);
-    if(ntop->getRedis()->get(rkey, rsp, sizeof(rsp)) == 0)
-      retval = atoi(rsp);
-  }
+  char rkey[128], rsp[16];
+  char ip_buf[48];
+  
+  snprintf(rkey, sizeof(rkey), "ntopng.prefs.%s:%d.flow_rate_alert_threshold",
+	   ip.print(ip_buf, sizeof(ip_buf)), vlan_id);
+  if(ntop->getRedis()->get(rkey, rsp, sizeof(rsp)) == 0)
+    retval = atoi(rsp);
 
   max_new_flows_sec_threshold = retval;
 }
 
+/* *************************************** */
+
 void Host::loadSynAlertPrefs() {
   int retval = CONST_MAX_NUM_SYN_PER_SECOND;
-
-  if(ip != NULL) {
-    char rkey[128], rsp[16];
-    char ip_buf[48];
-
-    snprintf(rkey, sizeof(rkey), "ntopng.prefs.%s:%d.syn_alert_threshold",
-             ip->print(ip_buf, sizeof(ip_buf)), vlan_id);
-    if(ntop->getRedis()->get(rkey, rsp, sizeof(rsp)) == 0)
-      retval = atoi(rsp);
-  }
+  char rkey[128], rsp[16];
+  char ip_buf[48];
+  
+  snprintf(rkey, sizeof(rkey), "ntopng.prefs.%s:%d.syn_alert_threshold",
+	   ip.print(ip_buf, sizeof(ip_buf)), vlan_id);
+  if(ntop->getRedis()->get(rkey, rsp, sizeof(rsp)) == 0)
+    retval = atoi(rsp);
 
   max_num_syn_sec_threshold = retval;
 }
 
+/* *************************************** */
+
 void Host::loadFlowsAlertPrefs() {
   u_int32_t retval = CONST_MAX_NUM_HOST_ACTIVE_FLOWS;
-
-  if(ip != NULL) {
-    char rkey[128], rsp[16];
-    char ip_buf[48];
-
-    snprintf(rkey, sizeof(rkey), "ntopng.prefs.%s:%d.flows_alert_threshold",
-             ip->print(ip_buf, sizeof(ip_buf)), vlan_id);
-    if(ntop->getRedis()->get(rkey, rsp, sizeof(rsp)) == 0)
-      retval = (u_int32_t)strtoul(rsp, NULL, 10);
-  }
+  char rkey[128], rsp[16];
+  char ip_buf[48];
+  
+  snprintf(rkey, sizeof(rkey), "ntopng.prefs.%s:%d.flows_alert_threshold",
+	   ip.print(ip_buf, sizeof(ip_buf)), vlan_id);
+  if(ntop->getRedis()->get(rkey, rsp, sizeof(rsp)) == 0)
+    retval = (u_int32_t)strtoul(rsp, NULL, 10);
 
   max_num_active_flows = retval;
 }
@@ -1382,7 +1299,7 @@ void Host::setDumpTrafficPolicy(bool new_policy) {
   else
     dump_host_traffic = new_policy;
 
-  snprintf(host, sizeof(host), "%s@%u", ip->print(buf, sizeof(buf)), vlan_id);
+  snprintf(host, sizeof(host), "%s@%u", ip.print(buf, sizeof(buf)), vlan_id);
 
   ntop->getRedis()->hashSet((char*)DUMP_HOST_TRAFFIC, host,
 			    (char*)(dump_host_traffic ? "true" : "false"));
@@ -1396,7 +1313,7 @@ void Host::readAlertPrefs() {
 
   if(!localHost) return;
 
-  if(ip && (!ip->isEmpty())) {
+  if(!ip.isEmpty()) {
     if(!ntop->getPrefs()->are_alerts_disabled()) {
       char *key, ip_buf[48];
 
@@ -1523,16 +1440,16 @@ void Host::incrVisitedWebSite(char *hostname) {
 /* *************************************** */
 
 void Host::setDeviceIfIdx(u_int32_t _ip, u_int16_t _v) {
-  char dev[48], port[16], value[128], buf[128];
+  char dev[48], port[16], value[128], buf[128], buf1[32];
 
   deviceIfIdx = _v, deviceIP = _ip;
 
   snprintf(dev, sizeof(dev), "flow_devs.%s", Utils::intoaV4(deviceIP, buf, sizeof(buf)));
   snprintf(port, sizeof(port), "%u", deviceIfIdx);
-  snprintf(value, sizeof(value), "%02X:%02X:%02X:%02X:%02X:%02X/%s",
-	   mac_address[0], mac_address[1], mac_address[2],
-	   mac_address[3], mac_address[4], mac_address[5],
-	   ip ? ip->print(buf, sizeof(buf)) : "0.0.0.0");
+
+  snprintf(value, sizeof(value), "%s/%s",
+	   Utils::formatMac(mac ? mac->get_mac() : NULL, buf1, sizeof(buf1)),
+	   ip.print(buf, sizeof(buf)));
 
   ntop->getRedis()->hashSet(dev, port, value);
 }
@@ -1540,79 +1457,83 @@ void Host::setDeviceIfIdx(u_int32_t _ip, u_int16_t _v) {
 /* *************************************** */
 
 void Host::incActivityBytes(UserActivityID id, u_int64_t upbytes, u_int64_t downbytes, u_int64_t bgbytes) {
-  user_activities.incBytes(id, upbytes, downbytes, bgbytes);
+  if(user_activities) user_activities->incBytes(id, upbytes, downbytes, bgbytes);
 }
 
 /* *************************************** */
 
-const UserActivityCounter * Host::getActivityBytes(UserActivityID id) {
-  return user_activities.getBytes(id);
+const UserActivityCounter* Host::getActivityBytes(UserActivityID id) {
+  return(user_activities ? user_activities->getBytes(id) : NULL);
 }
 
 /* *************************************** */
 
-void Host::incIfaPackets(ifa_stats_protos proto, const Flow * flow, time_t when) {
-  bool toadd = true;
-  int k = -1;
-  float mostbad = 0.f;
-  int i;
+void Host::incIfaPackets(InterFlowActivityProtos proto, const Flow * flow, time_t when) {
+  if(!ifa_stats)
+    return;
+  else {
+    bool toadd = true;
+    int k = -1;
+    float mostbad = 0.f;
+    int i;
 
-  for (i=0; i<INTER_FLOW_ACTIVITY_SLOTS && ifa_stats[proto][i].flow != flow; i++) {
-    float bad;
+    for (i=0; i<INTER_FLOW_ACTIVITY_SLOTS && ifa_stats[proto*i].flow != flow; i++) {
+      float bad;
     
-    if (ifa_stats[proto][i].flow == NULL)
-      // empty slot
-      bad = 1.f;
-    else
-      // old value: estimate goodness
-      bad = (when - ifa_stats[proto][i].last) * 1.f / INTER_FLOW_ACTIVITY_MAX_INTERVAL - ifa_stats[proto][i].pkts / 100.f;
+      if(ifa_stats[proto*i].flow == NULL)
+	// empty slot
+	bad = 1.f;
+      else
+	// old value: estimate goodness
+	bad = (when - ifa_stats[proto*i].last) * 1.f / INTER_FLOW_ACTIVITY_MAX_INTERVAL - ifa_stats[proto*i].pkts / 100.f;
 
-    if (bad > mostbad) {
-      k = i;
-      mostbad = bad;
-    }
-  }
-
-  if (i<INTER_FLOW_ACTIVITY_SLOTS) {
-    if ((when - ifa_stats[proto][i].last) <= INTER_FLOW_ACTIVITY_MAX_INTERVAL) {
-      // update slot
-      ifa_stats[proto][i].pkts += 1;
-      ifa_stats[proto][i].last = when;
-      toadd = false;
-    } else {
-      // reset slot counters
-      k = i;
-    }
-  }
-
-  if (toadd) {
-    // allocate or reset slot
-    ifa_stats[proto][k].flow = flow;
-    ifa_stats[proto][k].pkts = 1;
-    ifa_stats[proto][k].first = when;
-    ifa_stats[proto][k].last = when;
-  }
-}
-
-/* *************************************** */
-
-void Host::getIfaStats(ifa_stats_protos proto, time_t when, int * count, u_int32_t * packets, time_t * max_diff) {
-  *count = 0;
-  *max_diff = 0;
-  *packets = 0;
-  
-  for (int i=0; i<INTER_FLOW_ACTIVITY_SLOTS; i++) {
-    bool timeok = (when - ifa_stats[proto][i].last) <= INTER_FLOW_ACTIVITY_MAX_INTERVAL;
-    bool continuity = (when - ifa_stats[proto][i].last) <= INTER_FLOW_ACTIVITY_MAX_CONTINUITY_INTERVAL;
-    
-    if (continuity || timeok) {
-      if (timeok) {
-        *count += 1;
-        *max_diff = max(ifa_stats[proto][i].last - ifa_stats[proto][i].first, *max_diff);
+      if(bad > mostbad) {
+	k = i;
+	mostbad = bad;
       }
+    }
 
-      // this is affected by activity continuity
-      *packets += ifa_stats[proto][i].pkts;
+    if(i<INTER_FLOW_ACTIVITY_SLOTS) {
+      if((when - ifa_stats[proto*i].last) <= INTER_FLOW_ACTIVITY_MAX_INTERVAL) {
+	// update slot
+	ifa_stats[proto*i].pkts += 1;
+	ifa_stats[proto*i].last = when;
+	toadd = false;
+      } else {
+	// reset slot counters
+	k = i;
+      }
+    }
+
+    if(toadd) {
+      u_int idx = proto*k;
+      // allocate or reset slot
+      ifa_stats[idx].flow = flow, ifa_stats[idx].pkts = 1,
+	ifa_stats[idx].first = when, ifa_stats[idx].last = when;
+    }
+  }
+}
+
+/* *************************************** */
+
+void Host::getIfaStats(InterFlowActivityProtos proto, time_t when, 
+		       int * count, u_int32_t * packets, time_t * max_diff) {
+  *count = 0, *max_diff = 0, *packets = 0;
+  
+  if(ifa_stats) {
+    for(int i=0; i<INTER_FLOW_ACTIVITY_SLOTS; i++) {
+      bool timeok = (when - ifa_stats[proto*i].last) <= INTER_FLOW_ACTIVITY_MAX_INTERVAL;
+      bool continuity = (when - ifa_stats[proto*i].last) <= INTER_FLOW_ACTIVITY_MAX_CONTINUITY_INTERVAL;
+      
+      if(continuity || timeok) {
+	if(timeok) {
+	  *count += 1;
+	  *max_diff = max(ifa_stats[proto*i].last - ifa_stats[proto*i].first, *max_diff);
+	}
+	
+	// this is affected by activity continuity
+	*packets += ifa_stats[proto*i].pkts;
+      }
     }
   }
 }
diff --git a/src/HostHash.cpp b/src/HostHash.cpp
index 0890ba544a..4827e0ee17 100644
--- a/src/HostHash.cpp
+++ b/src/HostHash.cpp
@@ -57,6 +57,7 @@ Host* HostHash::get(u_int16_t vlanId, IpAddress *key) {
 
 /* ************************************ */
 
+#if 0
 Host* HostHash::get(u_int16_t vlanId, const u_int8_t mac[6]) {
   u_int32_t hash = 0;
 
@@ -87,6 +88,7 @@ Host* HostHash::get(u_int16_t vlanId, const u_int8_t mac[6]) {
     return(head);
   }
 }
+#endif
 
 /* ************************************ */
 
diff --git a/src/IpAddress.cpp b/src/IpAddress.cpp
index 95964ce83e..ff4c8904a7 100644
--- a/src/IpAddress.cpp
+++ b/src/IpAddress.cpp
@@ -31,47 +31,7 @@ IpAddress::IpAddress() {
 
 /* ******************************************* */
 
-IpAddress::IpAddress(char *string) {
-  ip_key = 0;
-  set_from_string(string);
-  compute_key();
-}
-
-/* ******************************************* */
-
-IpAddress::IpAddress(IpAddress *ip) {
-  ip_key = 0;
-  set(ip);
-}
-
-/* ******************************************* */
-
-IpAddress::IpAddress(u_int32_t _ipv4) {
-  ip_key = 0;
-  set_ipv4(_ipv4);
-  compute_key();
-}
-
-/* ******************************************* */
-
-IpAddress::IpAddress(struct ndpi_in6_addr *_ipv6) {
-  ip_key = 0;
-  set_ipv6(_ipv6);
-  addr.privateIP = false;
-  compute_key();
-}
-
-/* ******************************************* */
-
-void IpAddress::set(IpAddress *ip) {
-  memcpy(&addr, &ip->addr, sizeof(struct ipAddress));
-  ip_key = ip->ip_key;
-  compute_key();
-}
-
-/* ******************************************* */
-
-void IpAddress::set_from_string(char *sym_addr) {
+void IpAddress::set(char *sym_addr) {
   if(strchr(sym_addr, '.')) {
     addr.ipVersion = 4, addr.localHost = 0, addr.ipType.ipv4 = inet_addr(sym_addr);
   } else {
@@ -258,7 +218,7 @@ void IpAddress::deserialize(json_object *o) {
     addr.localHost = json_object_get_boolean(obj);
 
   if(json_object_object_get_ex(o, "ip", &obj))
-    set_from_string((char*)json_object_get_string(obj));
+    set((char*)json_object_get_string(obj));
 }
 
 /* ******************************************* */
diff --git a/src/Mac.cpp b/src/Mac.cpp
new file mode 100644
index 0000000000..fbbdf953b5
--- /dev/null
+++ b/src/Mac.cpp
@@ -0,0 +1,56 @@
+/*
+ *
+ * (C) 2013-16 - ntop.org
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ */
+
+#include "ntop_includes.h"
+
+/* *************************************** */
+
+Mac::Mac(NetworkInterface *_iface, u_int8_t _mac[6], u_int16_t _vlanId) : GenericHashEntry(_iface) {
+  memcpy(mac, _mac, 6), vlan_id = _vlanId;
+}
+
+/* *************************************** */
+
+Mac::~Mac() {
+  ;
+}
+
+/* *************************************** */
+
+bool Mac::isIdle(u_int max_idleness) {
+  if((num_uses > 0) || (!iface->is_purge_idle_interface()))
+    return(false);
+  
+  if(num_uses > 0) return(false);
+  
+  return(false);
+}
+
+/* *************************************** */
+
+bool Mac::idle() {
+  if((num_uses > 0) || (!iface->is_purge_idle_interface()))
+    return(false);
+  
+  return(isIdle(MAX_LOCAL_HOST_IDLE));
+}
+
+
diff --git a/src/MacHash.cpp b/src/MacHash.cpp
new file mode 100644
index 0000000000..7c4390ae83
--- /dev/null
+++ b/src/MacHash.cpp
@@ -0,0 +1,60 @@
+/*
+ *
+ * (C) 2013-16 - ntop.org
+ *
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software Foundation,
+ * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ */
+
+#include "ntop_includes.h"
+
+/* ************************************ */
+
+MacHash::MacHash(NetworkInterface *_iface, u_int _num_hashes, u_int _max_hash_size) : GenericHash(_iface, _num_hashes, _max_hash_size) {
+  ;
+}
+
+/* ************************************ */
+
+Mac* MacHash::get(u_int16_t vlanId, const u_int8_t mac[6]) {
+  u_int32_t hash = 0;
+
+  for(int i=0; i<6; i++) hash += mac[i] << (i+1);
+  hash %= num_hashes;
+
+  if(table[hash] == NULL) {
+    return(NULL);
+  } else {
+    Mac *head;
+
+    locks[hash]->lock(__FILE__, __LINE__);
+    head = (Mac*)table[hash];
+
+    while(head != NULL) {
+      if((!head->idle())
+         && (head->get_vlan_id() == vlanId)
+         && (memcmp(mac, head->get_mac(), 6) == 0))
+	break;
+      else
+        head = (Mac*)head->next();
+    }
+    
+    locks[hash]->unlock(__FILE__, __LINE__);
+    
+    return(head);
+  }
+}
+
diff --git a/src/NetworkInterface.cpp b/src/NetworkInterface.cpp
index 1ef3277d38..e33d23a172 100644
--- a/src/NetworkInterface.cpp
+++ b/src/NetworkInterface.cpp
@@ -122,6 +122,8 @@ NetworkInterface::NetworkInterface(const char *name) {
     num_hashes = max_val(4096, ntop->getPrefs()->get_max_num_hosts()/4);
     hosts_hash = new HostHash(this, num_hashes, ntop->getPrefs()->get_max_num_hosts());
 
+    macs_hash = new MacHash(this, 4, ntop->getPrefs()->get_max_num_hosts());
+
     // init global detection structure
     ndpi_struct = ndpi_init_detection_module();
     if(ndpi_struct == NULL) {
@@ -402,6 +404,7 @@ bool NetworkInterface::checkIdle() {
 void NetworkInterface::deleteDataStructures() {
   if(flows_hash) { delete(flows_hash); flows_hash = NULL; }
   if(hosts_hash) { delete(hosts_hash); hosts_hash = NULL; }
+  if(macs_hash)  { delete(macs_hash);  macs_hash = NULL;  }
 
   if(ndpi_struct) {
     ndpi_exit_detection_module(ndpi_struct);
@@ -913,13 +916,10 @@ bool NetworkInterface::processPacket(const struct bpf_timeval *when,
     /* non TCP/UDP protocols */
   }
 
-  if(iph != NULL) {
-    src_ip.set_ipv4(iph->saddr);
-    dst_ip.set_ipv4(iph->daddr);
-  } else {
-    src_ip.set_ipv6(&ip6->ip6_src);
-    dst_ip.set_ipv6(&ip6->ip6_dst);
-  }
+  if(iph != NULL)
+    src_ip.set(iph->saddr), dst_ip.set(iph->daddr);
+  else
+    src_ip.set(&ip6->ip6_src), dst_ip.set(&ip6->ip6_dst);  
 
 #if defined(WIN32) && defined(DEMO_WIN32)
   if(this->ethStats.getNumPackets() > MAX_NUM_PACKETS) {
@@ -1155,9 +1155,9 @@ void NetworkInterface::purgeIdle(time_t when) {
       ntop->getTrace()->traceEvent(TRACE_INFO, "Purged %u/%u idle flows on %s",
 				   n, getNumFlows(), ifname);
 
-    if((n = purgeIdleHosts()) > 0)
-      ntop->getTrace()->traceEvent(TRACE_INFO, "Purged %u/%u idle hosts on %s",
-				   n, getNumHosts(), ifname);
+    if((n = purgeIdleHostsMacs()) > 0)
+      ntop->getTrace()->traceEvent(TRACE_INFO, "Purged %u/%u idle hosts/macs on %s",
+				   n, getNumHosts()+getNumMacs(), ifname);
   }
 
   if(pkt_dumper) pkt_dumper->idle(when);
@@ -1510,18 +1510,11 @@ bool NetworkInterface::dissectPacket(const struct pcap_pkthdr *h,
     break;
 
   default: /* No IPv4 nor IPv6 */
-    Host *srcHost = findHostByMac(ethernet->h_source, vlan_id, true);
-    Host *dstHost = findHostByMac(ethernet->h_dest, vlan_id, true);
+    Mac *srcMac = getMac(ethernet->h_source, vlan_id, true);
+    Mac *dstMac = getMac(ethernet->h_dest, vlan_id, true);
 
-    if(srcHost) {
-      srcHost->incStats(0, NO_NDPI_PROTOCOL, NULL, 1, h->len, h->len-ip_offset, 0, 0, 0);
-      srcHost->updateActivities();
-    }
-
-    if(dstHost) {
-      dstHost->incStats(0, NO_NDPI_PROTOCOL, NULL, 0, 0, 0, 1, h->len, h->len-ip_offset);
-      dstHost->updateActivities();
-    }
+    if(srcMac) srcMac->incSentStats(h->len);
+    if(dstMac) dstMac->incRcvdStats(h->len);
 
     incStats(h->ts.tv_sec, eth_type, NDPI_PROTOCOL_UNKNOWN, h->len,
 	     1, 24 /* 8 Preamble + 4 CRC + 12 IFG */);
@@ -1803,9 +1796,11 @@ Host* NetworkInterface::getHost(char *host_ip, u_int16_t vlan_id) {
 
     h = info.h;
   } else {
-    IpAddress *ip = new IpAddress(host_ip);
+    IpAddress *ip = new IpAddress();
 
     if(ip) {
+      ip->set(host_ip);
+
       if(!isView())
 	h = hosts_hash->get(vlan_id, ip);
       else {
@@ -1897,7 +1892,6 @@ Host* NetworkInterface::findHostsByIP(patricia_tree_t *allowed_hosts,
 
 /* **************************************************** */
 
-
 struct flowHostRetrieveList {
   Flow *flow;
   /* Value */
@@ -2661,28 +2655,20 @@ void NetworkInterface::getFlowPeersList(lua_State* vm,
 
 /* **************************************************** */
 
-class HostActivityRetriever {
-public:
-  IpAddress search;
-  bool found;
-  UserActivityCounter counters[UserActivitiesN];
-
-  HostActivityRetriever(const char * ip) : search((char *)ip) { found = false; };
-};
-
-/* **************************************************** */
-
 static bool host_activity_walker(GenericHashEntry *he, void *user_data) {
   HostActivityRetriever * r = (HostActivityRetriever *)user_data;
   Host *h = (Host*)he;
   int i;
 
-  if(!h || !h->equal(&r->search))
-    return (false); /* false = keep on walking */
+  if(!h 
+     || !h->equal(&r->search) 
+     || (!h->get_user_activities()))
+    return(false); /* false = keep on walking */
 
   r->found = true;
   for(i=0; i<UserActivitiesN; i++)
-    r->counters[i] = *h->getActivityBytes((UserActivityID) i);
+    r->counters[i] = *h->getActivityBytes((UserActivityID)i);
+
   return true; /* found, stop walking */
 }
 
@@ -2784,7 +2770,15 @@ u_int NetworkInterface::getNumHTTPHosts()    {
 
 /* **************************************************** */
 
-u_int NetworkInterface::purgeIdleHosts() {
+u_int NetworkInterface::getNumMacs()        {
+  u_int tot = macs_hash ? macs_hash->getNumEntries() : 0;
+  for(u_int8_t s = 0; s<numSubInterfaces; s++) tot += subInterfaces[s]->getNumMacs();
+  return(tot);
+};
+
+/* **************************************************** */
+
+u_int NetworkInterface::purgeIdleHostsMacs() {
   if(!purge_idle_flows_hosts) return(0);
 
   if(next_idle_host_purge == 0) {
@@ -2797,7 +2791,7 @@ u_int NetworkInterface::purgeIdleHosts() {
     u_int n;
 
     // ntop->getTrace()->traceEvent(TRACE_INFO, "Purging idle hosts");
-    n = hosts_hash->purgeIdle();
+    n = hosts_hash->purgeIdle() + macs_hash->purgeIdle();
     next_idle_host_purge = last_pkt_rcvd + HOST_PURGE_FREQUENCY;
     return(n);
   }
@@ -3000,23 +2994,23 @@ void NetworkInterface::runHousekeepingTasks() {
 
 /* **************************************************** */
 
-Host* NetworkInterface::findHostByMac(u_int8_t mac[6], u_int16_t vlanId,
-				      bool createIfNotPresent) {
-  Host *ret;
-
+Mac* NetworkInterface::getMac(u_int8_t _mac[6], u_int16_t vlanId,
+			      bool createIfNotPresent) {
+  Mac *ret;
+  
   if(!isView())
-    ret = hosts_hash->get(vlanId, mac);
+    ret = macs_hash->get(vlanId, _mac);
   else {
     for(u_int8_t s = 0; s<numSubInterfaces; s++) {
-      if((ret = subInterfaces[s]->get_hosts_hash()->get(vlanId, mac)) != NULL)
+      if((ret = subInterfaces[s]->get_macs_hash()->get(vlanId, _mac)) != NULL)
 	break;
     }
   }
 
   if((ret == NULL) && createIfNotPresent) {
     try {
-      if((ret = new Host(this, mac, vlanId)) != NULL)
-	hosts_hash->add(ret);
+      if((ret = new Mac(this, _mac, vlanId)) != NULL)
+	macs_hash->add(ret);
     } catch(std::bad_alloc& ba) {
       static bool oom_warning_sent = false;
 
@@ -3027,8 +3021,7 @@ Host* NetworkInterface::findHostByMac(u_int8_t mac[6], u_int16_t vlanId,
 
       return(NULL);
     }
-  } else
-    ret->updateLocal();
+  }
 
   return(ret);
 }
@@ -3244,7 +3237,6 @@ static bool similarity_walker(GenericHashEntry *node, void *user_data) {
   return(false); /* false = keep on walking */
 }
 
-
 /* **************************************************** */
 
 bool NetworkInterface::correlateHostActivity(lua_State* vm,
@@ -3260,6 +3252,7 @@ bool NetworkInterface::correlateHostActivity(lua_State* vm,
     info.vm = vm, info.h = h;
     h->getActivityStats()->extractPoints(&info.x);
     walker(true, correlator_walker, &info);
+
     return(true);
   } else
     return(false);
@@ -3280,6 +3273,7 @@ bool NetworkInterface::similarHostActivity(lua_State* vm,
     info.vm = vm, info.h = h;
     h->getActivityStats()->extractPoints(&info.x);
     walker(true, similarity_walker, &info);
+
     return(true);
   } else
     return(false);
diff --git a/src/ParserInterface.cpp b/src/ParserInterface.cpp
index 656b163da6..36cef23538 100755
--- a/src/ParserInterface.cpp
+++ b/src/ParserInterface.cpp
@@ -567,9 +567,9 @@ u_int8_t ParserInterface::parseFlow(char *payload, int payload_size, u_int8_t so
 	     v6 address may overwrite the non empty v4.
 	   */
 	  if(flow.src_ip.isEmpty()) {
-	    flow.src_ip.set_from_string((char*)value);
+	    flow.src_ip.set((char*)value);
 	  } else {
-	    ip_aux.set_from_string((char*)value);
+	    ip_aux.set((char*)value);
 	    if(!ip_aux.isEmpty())
 	      /* tried to overwrite a non-empty IP with another non-empty IP */
 	      ntop->getTrace()->traceEvent(TRACE_WARNING,
@@ -580,9 +580,9 @@ u_int8_t ParserInterface::parseFlow(char *payload, int payload_size, u_int8_t so
         case IPV4_DST_ADDR:
         case IPV6_DST_ADDR:
 	  if(flow.dst_ip.isEmpty()) {
-	    flow.dst_ip.set_from_string((char*)value);
+	    flow.dst_ip.set((char*)value);
 	  } else {
-	    ip_aux.set_from_string((char*)value);
+	    ip_aux.set((char*)value);
 	    if(!ip_aux.isEmpty())
 	      ntop->getTrace()->traceEvent(TRACE_WARNING,
 					   "Attempt to set destination ip multiple times. "
diff --git a/src/Prefs.cpp b/src/Prefs.cpp
index d5dc1f70a4..1904823d30 100755
--- a/src/Prefs.cpp
+++ b/src/Prefs.cpp
@@ -958,8 +958,8 @@ int Prefs::setOption(int optkey, char *optarg) {
     break;
     
   case 216:
-      enable_flow_activity = true;
-      ntop->getTrace()->traceEvent(TRACE_NORMAL, "Flow activity detection enabled");
+    enable_flow_activity = true;
+    ntop->getTrace()->traceEvent(TRACE_NORMAL, "Flow activity detection enabled");
     break;
 
 #ifdef NTOPNG_PRO
diff --git a/src/Utils.cpp b/src/Utils.cpp
index 5d7987e39b..ef9f94b51d 100755
--- a/src/Utils.cpp
+++ b/src/Utils.cpp
@@ -1320,23 +1320,31 @@ bool Utils::discardOldFilesExceeding(const char *path, const unsigned long max_s
 
 /* **************************************** */
 
-
-char* Utils::macaddr_str (const char *mac, char *buf) {
-  sprintf(buf, "%02X:%02X:%02X:%02X:%02X:%02X",
-          mac[0] & 0xFF, mac[1] & 0xFF, mac[2] & 0xFF,
-          mac[3] & 0xFF, mac[4] & 0xFF, mac[5] & 0xFF);
+char* Utils::formatMac(u_int8_t *mac, char *buf, u_int buf_len) {
+  if(mac == NULL)
+    snprintf(buf, buf_len, "00:00:00:00:00:00");
+  else
+    snprintf(buf, buf_len, "%02X:%02X:%02X:%02X:%02X:%02X",
+	   mac[0] & 0xFF, mac[1] & 0xFF,
+	   mac[2] & 0xFF, mac[3] & 0xFF,
+	   mac[4] & 0xFF, mac[5] & 0xFF);    
   return(buf);
 }
 
 /* **************************************** */
 
+u_int64_t Utils::macaddr_int(const u_int8_t *mac) {
+  if(mac == NULL)
+    return(0);
+  else {
+    u_int64_t mac_int = 0;
 
-u_int64_t Utils::macaddr_int (const u_int8_t *mac) {
-  u_int64_t mac_int = 0;
-  for(u_int8_t i=0; i<6; i++){
-    mac_int |= (mac[i] & 0xFF) << (5-i)*8;
+    for(u_int8_t i=0; i<6; i++){
+      mac_int |= (mac[i] & 0xFF) << (5-i)*8;
+    }
+    
+    return mac_int;
   }
-  return mac_int;
 }
 
 /* **************************************** */
@@ -1373,7 +1381,7 @@ void Utils::readMac(char *_ifname, dump_mac_t mac_addr) {
 
   ntop->getTrace()->traceEvent(TRACE_INFO, "Interface %s has MAC %s",
 			       ifname,
-			       macaddr_str((char *)mac_addr, mac_addr_buf));
+			       formatMac((char *)mac_addr, mac_addr_buf, sizeof(mac_addr_buf)));
   close(_sock);
 }
 #else