Ntop
Ntop is a network traffic probe based on libcap, that offers RMON-like network traffic statistics accessible via a web browser.
Contents
Installation and configuration
Install the ntop package. The first run of ntop, you must set the admin password:
# ntop
Next, you need to edit the configuration file (/etc/conf.d/ntop
) to adapt on your needs. Below is an example configuration, with the focus on the host to get as much as information from the hosts connections:
/etc/conf.d/ntop
# Parameters to be passed to ntop. NTOP_ARGS="-K -W 2323 -i enp1s0,wlp2s0 -M -s -4 -6 -s -u ntop -c -r 30 --w3c -t 3 -a /var/log/ntop/http.log -O /var/log/ntop/ -q --skip-version-check 0" # Location of the log file. NTOP_LOG="/var/log/ntop/ntop.log"
Before starting and possibly enabling the ntop
service, you may have to edit its ntop command options:
/etc/systemd/system/ntop.d/options.conf
[Service] ExecStart= ExecStart=/usr/bin/ntop options
Tips and tricks
Web interface
To access ntop's web interface, enter http://127.0.0.1:3000/ into your web browser. To make changes to the server, you will need to enter your username (default = admin) and password.
If ntop is not just used locally on your machine, but network wide by multiple users, you'd be better off by allowing SSL connections (https) only.
# ntop -W 4223
On firefox, the self-signed certificat should be a problem. Page will not be shown like that.
Additional paramethers are allowed. Now direct our browser to https://127.0.0.1:4223/.
You can also provide ntop with your own SSL certificate. Simply put it in ntop's config directory and name it ntop-cert.pem
# cd /usr/share/ntop # openssl req -x509 -nodes -days 365 \-subj '/C=US/L=Portland/CN=swim' \-newkey rsa:1024 -keyout ntop-cert.pem -out ntop-cert.pem
Instead of make a self-signed certificat who will make your page unable to print on firefox, you should look at letsencrypt service. This service will make a free well recognized certificat for your domain. Then you will have to copy privkey.pem and fullchain.pem inside ntop-cert.pem:
# cat /etc/letsencrypt/live/<your domain>/privkey.pem /etc/letsencrypt/live/>your domain>/fullchain.pem > /usr/share/ntop/ntop-cert.pem
you can also copy your private key in the same place.
Group and user
In order for the -u parameter to work properly and to make your ntop setup a bit more secure, you should create your own group and user for it.
# useradd -M -s /usr/bin/false ntop # passwd -l ntop
passwd
command here is optional, but recommended, as it will render the system more secure regarding your sshd.Troubleshooting
**ERROR** RRD: Disabled - unable to create base directory (err 13, /var/lib/ntop/rrd)
Directory /var/lib/ntop/rrd/
may not exist. Create it and make sure it belongs to user nobody.
Please enable make sure that the ntop html/ directory is properly installed
If you receive this warning while trying to access the web interface, edit /etc/conf.d/ntop
to include your IP and restart the daemon. For example:
NTOP_ARGS="-i enp1s0 -w 127.0.0.1:3000"
This is the IP you will use to access the web interface.