ntopng is the new rewritten version of ntop. By default it listens on port 3000. This is the same port as ntop. Therefore, if you have ntop running, you will need to disable ntop or to change the port ntopng is listening on. To change the port ntopng is listening on, or on what interfaces to sniff on, you need to edit /etc/default/ntopng. The default credentials for the web UI are: username: admin password: admin You can change via the Admin menu in the web UI. See README.users for more details. The ntopng User Guide from upstream documentation can be found at https://svn.ntop.org/svn/ntop/trunk/ntopng/doc/UserGuide.pdf?p=8031