ran snort, now fxp1 stuck in promisc mode

[Lowell Gilbert]

"Dave [Hawk-Systems]" <dave at hawk-systems.com> writes:

> was experimenting with snort to try and track down the source of some hack
> attempts (which were futile but annoying).  Before settling on the various flags
> that I indeed wanted to use, there were a number of failed snort starts, stops,
> etc...  don't remember the specifics now as this was some time ago.
> 
> Have noticed that since then the fxp1 interface has been stuck in promisc mode.
> 
> 	fxp1: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> mtu 1500
> 
> Have tried manually to unset this using;
> 	# ifconfig -promisc fxp1
> to no avail.
> 
> snort is no longer running, though when I do start it to track something, I have
> since been running it with the -p flag to turn off promisc sniffing.  This
> doesn't seem to affect the interface since it is already in promisc mode.
> 
> This box is regularly checked for root kits or other potential comprimises that
> could have caused this, and we did notice it after the first few unsuccessful
> attempts with snort in promisc mode so we are pretty sure of the source.
> 
> Aside from rebooting the box entirely (undesireable given it is a production
> server) anyone have any ideas as to how to force fxp1 to let go of its promisc
> fetish?

Hmm.  I don't see how this can happen (on -STABLE, anyway), but it's
worth poking it a bit to see what happens.  You could take the
interface down and back up, and try to force the itnerface *into*
promiscuous mode and then back out again.