I am totally out of ideas on what coud be causing this... so would be interested to hear any suggestions.

I'm running the latest build of Debian (base build only) and have installed the latest version of Nessus. I might add that Debian is running as a VMWare virtual server on top of Windows XP but I think thats irrelevent (or rather, hope!)

Anyway.. everything works fine, connectivity is fine. Package downloads over several hours have been successful....

BUT... when I do a scan with Nessus.... about 30% into a scan (on the first host) I lose connectivity. What I mean is... my continuous ping (which I am also running for demonstration purpose) times out with a "destination unreachable". Obviously the scan fails as well.

The only thing that will recover the connectivity.. is unplugging the cable from the ethernet port, and plugging it back in again. Not even re-booting Debian,or re-starting VMWare will do it.. it must be the physical cable or an entire reboot of the laptop.

I can't figure out how simply scanning a host (even lightly using only 2 simultanous TCP sessions at a time) could completely mess up the core network connectivity of Debian every time in such a way.

It seems to be Nessus, because Debian works perfectly all the time... but I just can't understand how Nessus could mess up the Debian core networking components when it's basically a network app.