diff --git a/include/SNMP.h b/include/SNMP.h
index a0283f061e..be6fa1ece7 100644
--- a/include/SNMP.h
+++ b/include/SNMP.h
@@ -39,7 +39,7 @@ class SNMP {
   int snmp_read_response(lua_State* vm, u_int timeout);
   
   public:
-  SNMP(u_int8_t version = 1 /* SNMPv2c */);
+  SNMP();
   ~SNMP();
 
   void send_snmp_request(char *agent_host, char *community, bool isGetNext,
diff --git a/include/ntop_defines.h b/include/ntop_defines.h
index e8d23c3457..5f7331ef21 100644
--- a/include/ntop_defines.h
+++ b/include/ntop_defines.h
@@ -468,6 +468,7 @@
 #define CONST_HOST_FLOW_VICTIM_ALERT_THRESHOLD_KEY     "flow_victim_threshold"
 #define CONST_RUNTIME_PREFS_NBOX_INTEGRATION           "ntopng.prefs.nbox_integration" /* 0 / 1 */
 #define CONST_RUNTIME_PREFS_LOGGING_LEVEL              "ntopng.prefs.logging_level"
+#define CONST_RUNTIME_PREFS_SNMP_PROTO_VERSION         "ntopng.prefs.default_snmp_version"
 #define CONST_RUNTIME_PREFS_IFACE_FLOW_COLLECTION      "ntopng.prefs.dynamic_flow_collection_mode" /* {"none", "vlan", "probe_ip","ingress_iface_idx"} */
 #define CONST_RUNTIME_PREFS_LAN_INTERFACE              "ntopng.prefs.network.lan_if"
 #define CONST_RUNTIME_PREFS_WAN_INTERFACE              "ntopng.prefs.network.wan_if"
diff --git a/scripts/locales/en.lua b/scripts/locales/en.lua
index fd10464294..7f87bb9669 100644
--- a/scripts/locales/en.lua
+++ b/scripts/locales/en.lua
@@ -781,6 +781,8 @@ local  en = {
 	 " will be created an RRD with ingress/egress bytes.",
       default_snmp_community_title = "Default SNMP Community",
       default_snmp_community_description = "The default SNMP community is used when trying to walk the SNMP MIB of a selected local host that has not been configured through the SNMP devices page.",
+      default_snmp_proto_version_title = "Default SNMP Version",
+      default_snmp_proto_version_description = "The default SNMP protocol version.",
       nbox_integration = "nBox Integration",
       toggle_nbox_integration_title = "Enable nBox Support",
       toggle_nbox_integration_description = "Enable sending ntopng requests (e.g., to download pcap files) to an nBox. Pcap requests are issued "..
diff --git a/scripts/lua/admin/prefs.lua b/scripts/lua/admin/prefs.lua
index 70394162da..1149431ae8 100644
--- a/scripts/lua/admin/prefs.lua
+++ b/scripts/lua/admin/prefs.lua
@@ -292,7 +292,7 @@ function printExternalAlertsReport()
 
   local retVal = multipleTableButtonPrefs(subpage_active.entries["slack_notification_severity_preference"].title, subpage_active.entries["slack_notification_severity_preference"].description,
                labels, values, "only_errors", "primary", "slack_notification_severity_preference",
-	       "ntopng.prefs.alerts.slack_alert_severity", nil, nil, nil,  nil, showElements and showSlackNotificationPrefs)
+	       "ntopng.prefs.alerts.slack_alert_severity", nil, nil, nil, nil, showElements and showSlackNotificationPrefs)
 
   prefsInputFieldPrefs(subpage_active.entries["sender_username"].title, subpage_active.entries["sender_username"].description,
            "ntopng.prefs.alerts.", "sender_username",
@@ -973,6 +973,12 @@ function printSnmp()
     disabled = not info["version.enterprise_edition"],
   })
 
+  local t_labels = {"v1", "v2c"}
+  local t_values = {"0", "1"}
+
+  multipleTableButtonPrefs(subpage_active.entries["default_snmp_proto_version"].title, subpage_active.entries["default_snmp_proto_version"].description,
+			   t_labels, t_values, "0", "primary", "default_snmp_version", "ntopng.prefs.default_snmp_version")
+  
   prefsInputFieldPrefs(subpage_active.entries["default_snmp_community"].title, subpage_active.entries["default_snmp_community"].description,
 		       "ntopng.prefs.",
 		       "default_snmp_community",
diff --git a/scripts/lua/modules/http_lint.lua b/scripts/lua/modules/http_lint.lua
index 3ce0118977..df023888bb 100644
--- a/scripts/lua/modules/http_lint.lua
+++ b/scripts/lua/modules/http_lint.lua
@@ -693,6 +693,12 @@ local function validateInterfaceConfMode(m)
    return validateChoice({"dhcp", "static"}, m)
 end
 
+-- #################################################################
+
+local function validateSNMPversion(m)
+   return validateChoice({"0", "1"}, m)
+end
+
 -- #################################################################
 -- NOTE: Put here al the parameters to validate
 
@@ -842,6 +848,7 @@ local known_parameters = {
    ["zoom"]                    =  validateZoom,                  -- a graph zoom specifier
    ["community"]               =  validateSingleWord,            -- SNMP community
    ["default_snmp_community"]  =  validateSingleWord,            -- Default SNMP community for non-SNMP-configured local hosts
+   ["default_snmp_version"]    =  validateSNMPversion,           -- Default SNMP protocol version
    ["snmp_port_idx"]           =  validateNumber,                -- SNMP port index
    ["snmp_recache" ]           =  validateBool,                  -- forces SNMP queries to be re-executed and cached
    ["request_discovery" ]      =  validateBool,                  -- forces device discovery to be re-cached
diff --git a/scripts/lua/modules/prefs_menu.lua b/scripts/lua/modules/prefs_menu.lua
index 514cf3c9ef..9aa11d0c03 100644
--- a/scripts/lua/modules/prefs_menu.lua
+++ b/scripts/lua/modules/prefs_menu.lua
@@ -199,6 +199,9 @@ local menu_subpages = {
     }, default_snmp_community = {
       title       = i18n("prefs.default_snmp_community_title"),
       description = i18n("prefs.default_snmp_community_description"),
+    }, default_snmp_proto_version = {
+       title       = i18n("prefs.default_snmp_proto_version_title"),
+       description = i18n("prefs.default_snmp_proto_version_description"),
     },
   }}, {id="nbox",          label=i18n("prefs.nbox_integration"),     advanced=true,  pro_only=true,   disabled=false, entries={
     toggle_nbox_integration = {
diff --git a/src/NetworkInterface.cpp b/src/NetworkInterface.cpp
index 848c1c653f..4d8a4c0a87 100644
--- a/src/NetworkInterface.cpp
+++ b/src/NetworkInterface.cpp
@@ -4665,7 +4665,8 @@ void NetworkInterface::getnDPIProtocols(lua_State *vm, ndpi_protocol_category_t
   for(i=0; i<(int)ndpi_struct->ndpi_num_supported_protocols; i++) {
     char buf[8];
 
-    if(((filter == (u_int8_t)-1) || ndpi_struct->proto_defaults[i].protoCategory == filter) &&
+    if((((u_int8_t)filter == (u_int8_t)-1)
+	|| ndpi_struct->proto_defaults[i].protoCategory == filter) &&
 	(!skip_critical || !Utils::isCriticalNetworkProtocol(i))) {
       snprintf(buf, sizeof(buf), "%d", i);
       lua_push_str_table_entry(vm, ndpi_struct->proto_defaults[i].protoName, buf);
diff --git a/src/SNMP.cpp b/src/SNMP.cpp
index 20bb4f54ad..ae953bd546 100644
--- a/src/SNMP.cpp
+++ b/src/SNMP.cpp
@@ -29,12 +29,17 @@ extern "C" {
 
 /* ******************************* */
 
-SNMP::SNMP(u_int8_t version) {
+SNMP::SNMP() {
+  char version[4] = { '\0' };
+
+  ntop->getRedis()->get((char*)CONST_RUNTIME_PREFS_SNMP_PROTO_VERSION, version, sizeof(version));
+
   if((udp_sock = socket(AF_INET, SOCK_DGRAM, 0)) < 0)
     throw("Unable to start network discovery");
-
+  
   Utils::maximizeSocketBuffer(udp_sock, true /* RX */, 2 /* MB */);
-  snmp_version = version;
+  snmp_version = atoi(version);
+  if(snmp_version > 1 /* v2c */) snmp_version = 1;
 }
 
 /* ******************************* */