Home page logo

snort logo Snort mailing list archives

Not-ing out ports
From: John Wiltberger <johwiltb () gmail com>
Date: Mon, 13 May 2013 07:01:19 -0400

So I have a question.  When dealing with bi-directional signatures (I know,
they aren't ideal in the least, but sometimes you can't help who develops
your signatures), if you choose to not-out a port (as in !<port number>),
does snort run a boolean OR on the traffic (as in 'if source port != <port
number OR destination port != <port number>)?

Reason is, I have a signature that's header is 'alert tcp any any <> any
!25', yet it is still alerting off of traffic over port 25.  I'm sorry if
these seems confusing, I can't think of a better way of stating this.  Any
Learn Graph Databases - Download FREE O'Reilly Book
"Graph Databases" is the definitive new guide to graph databases and 
their applications. This 200-page book is written by three acclaimed 
leaders in the field. The early access version is available now. 
Download your free book today! http://p.sf.net/sfu/neotech_d2d_may
Snort-sigs mailing list
Snort-sigs () lists sourceforge net

Please visit http://blog.snort.org for the latest news about Snort!

  By Date           By Thread  

Current thread:
[ Nmap | Sec Tools | Mailing Lists | Site News | About/Contact | Advertising | Privacy ]