Snort mailing list archives

Re: porno rules


From: Matt Kettler <mkettler () evi-inc com>
Date: Tue, 29 Apr 2003 21:56:56 -0400

At 05:10 PM 4/29/2003 -0700, Bryan Irvine wrote:
I've figured it out.

I changed this "flow:to_client,established;" to this "flags:A+;"

I'm very new to snort. I installed it for the first time right before
2.0-release came out.  What do these 2 options do?

flow:to_client,established:

The packet must be flowing to the client half of the TCP 3 way handshake (ie: the one that started the connection in the first place) and must be in an established state (ie: not part of the 3 way handshake or the teardown sequence).

Note that flows seem to require that stream4 be enabled to work correctly.

flags:A+:

The packet must have the TCP ack bit set. Other bits may be set as well and are treated as "don't care". This has a somewhat similar effect to the "established" part of the flow, but it's stateless so it will also match a "stray ack packet" that isn't associated with an existing connection.








-------------------------------------------------------
This sf.net email is sponsored by:ThinkGeek
Welcome to geek heaven.
http://thinkgeek.com/sf
_______________________________________________
Snort-users mailing list
Snort-users () lists sourceforge net
Go to this URL to change user options or unsubscribe:
https://lists.sourceforge.net/lists/listinfo/snort-users
Snort-users list archive:
http://www.geocrawler.com/redir-sf.php3?list=snort-users


Current thread: