The synaptics version of Nessus it is on version 2 (opensource), on official website of Nessus you can get the latest version.
- download Nessus and NessusClient depending of your distro and your processor arch
- reproduce the following steps
sudo dpkg -i Nessus-XXXXX.deb sudo dpkg -i NessusClient-XXXXX.deb
- Get an activation code for update nessus plugins: register in nessus website at plugins section, click on request an activation code, then click on Register a HomeFeed, then go to your email
/opt/nessus/bin/nessus-fetch --register XXXX-XXXX-XXXX-XXXX-XXXX
- adding an user, on Authentication (pass/cert) you can press enter ...
- starting nessus deamon (server)
sudo /etc/init.d/nessusd start
- now its time to run nessus client (gui), also you can run from NessusClient shortcut (look for your desktop environment applications menu)