ntopng/doc

Building ntopng

See README.compilation for more information.

Prior to Starting ntopng

Please make sure that you have a Redis server installed and active on the same host where ntopng will be running. If you plan to use a remote Redis server, please consider using the --redis option to specify a remote Redis server IP address and port or a local socket. We suggest you run Redis as a service so that you do not have to start it every time you want to use ntopng.

Using ntopng as a flow collector

In order to use ntopng as a flow collector with nprobe you need to start the apps as follows:

• collector

  • ntopng -i tcp://127.0.0.1:5556

• probe (nProbe)

  • nprobe --zmq "tcp://*:5556" -i ethX -n none -b 2

You can instruct ntopng to merge onto the same interface multiple endpoints by separating them with a comma. Example:

ntopng -i tcp://127.0.0.1:5556,tcp://192.168.0.1:5556

Creating Hierarchies of ntopng Instances

You can create a hierarchy of ntopngs (e.g. on a star topology, where you have many ntopng processes on the edge of a network and a central collector) as follows:

• Remote ntopng's

  • Host 1.2.3.4 ntopng -i ethX -I "tcp://*:3456"
  • Host 1.2.3.5 ntopng -i ethX -I "tcp://*:3457"
  • Host 1.2.3.6 ntopng -i ethX -I "tcp://*:3458"

• Central ntopng

  • ntopng -i "tcp://1.2.3.4:3456" -i "tcp://1.2.3.5:3457" -i "tcp://1.2.3.6:3458"

Note that on the central ntopng you can add -i ethX if you want the central ntopng monitor a local interface as well.

Accessing ntopng URLs from command line tools (no web browser)

You need to specify the user and password as specified below (please note the space in the cookie). Note that you can optionally also specify the interface name.

curl --cookie "user=admin; password=admin" "http://127.0.0.1:3000/lua/rest/get/interface/data.lua?ifid=0"

Using ntopng from Windows

1. Remember to start the Redis server prior to start ntopng
2. You must start ntopng as a service using the "Services" control panel

Defaults

The ntopng default user is 'admin' (without ') and the default password is also 'admin' (without ')

Unable to Login

Check out https://www.ntop.org/guides/ntopng/faq.html#cannot-login-into-the-gui

Running multiple ntopng instances on the same host

In order to run multiple ntopng instances independently (i.e. they do not interfere each other), each instance must:

1. Set a different value for -d
2. Set a different database id for -r
3. Use a different http port iwth -w

Example:

• ntopng -d /path1 -r 127.0.0.1:6379@1 -w 3001
• ntopng -d /path2 -r 127.0.0.1:6379@2 -w 3002 ...

In case you save timseries in InfluxDB, make sure you use a different DB per instance in order not to mix data across instances.

Using Interface Views

Suppose you want to start ntopng as follows -i eth0 -i eth1. ntopng will show you traffic of these two interfaces without any merge so you can see exactly what happens on each interface. If you also need an aggregated view of both interfaces you can start ntopng as ntopng -i eth0 -i eth1 -i view:eth0,eth1 so ntopng will create a virtual interface that merges information from the two physical interfaces.

Accessing ntopng behind a Reverse Proxy

If you have many ntopng instances that you want to mask behind a proxy the -Z option is what you look for. See the man page for more information.

Using ntopng with a HTTP(S) Proxy

If in your network you need to use a proxy to access the Internet, you need to set in your environment the HTTP_PROXY to use and ntopng will use it. Both HTTP and HTTPS URLs are supported.

Example:

• export HTTP_PROXY=http://127.0.0.1:1234
• ntopng -i eth0

If you start ntopng from systemd you need to edit /etc/systemd/system.conf and set:

• DefaultEnvironment=http://127.0.0.1:1234

Traffic with sampling rate

If you apply a sampling rate to capture traffic on an interface, say x100, the traffic volume you see on ntopng will be 100 times smaller. In order to simulate more traffic to match real traffic volume, you can apply a scaling factor to the size of each received packet. The scaling factor can be specified through the GUI, into the interface settings.

Debugging ntopng

handle SIGPIPE nostop noprint pass