[Snort-users] snort behind firewall ??

Steve Halligan agent33 at ...187...
Thu Apr 26 20:31:35 EDT 2001

a ppp0 int is at layer2...so ipchains will block it and snort wont see it.
If you had a ethernet int on the outside, pcap would be able to see the
packets before ipchains blocked it.

> Don't know, guys, really.
> I run snort on the same linux machine I use ipchains.
> I configured it to serve and protect my ppp0 interface.
> Until today, it has alerted me of nothing but an ICMP scan, thanks to 
> ipchains.
> The moment I remove ipchains, snort usually begins its barking.
> And of course I heavily tested it with self initiated scannings.
> My conclusion, and of course your remarks are more than 
> welcomed, is that
> snort  DO  NOT   see packets blocked by ipchains.

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