Re: tcp rules not working

[James Lay <jlay () slave-tothe-box net>]

Your TCP flow will have a state.  Try flow:established.
James
On Wed, 2017-02-15 at 22:23 +0000, Michael J. Sheldon wrote:
> I'm testing snort for use filtering DNS traffic. I have it set up
> using nfq inline
>
> This rule works exactly as expected (drops requests for www.example.c
> om):
> drop udp any any -> $HOME_NET $DNS_PORTS (msg:"TEST example.com";
> flow:stateless; content:"|03|www|07|example|03|com|00|"; nocase;
> offset:12; sid:3100001; rev:1;)
>
> This rule also works (alerts for all tcp inbound):
> alert tcp any any -> $HOME_NET $DNS_PORTS (msg:"TEST all tcp";
> sid:3100003; rev:1;)
>
> This rule does NOT work:
> drop tcp any any -> $HOME_NET $DNS_PORTS (msg:"TEST example.com";
> flow:stateless; content:"|07|example|03|com|00|"; nocase; offset:12;
> sid:3100002; rev:1;)
>
> After a LOT of playing with the rules, no matter what, if the
> protocol is TCP, and there is a "content" parameter at all, the rule
> will not match. tried variations on flow (stateless, to_server,
> to_client, etc)
>
> I've got to be missing something incredibly simple, but at this
> point, no idea what it is.
>
> Michael Sheldon
> Dev-DNS Services
> GoDaddy.com
>
> -------------------------------------------------------------------
> -----------
> Check out the vibrant tech community on one of the world's most
> engaging tech sites, SlashDot.org! http://sdm.link/slashdot
> _______________________________________________
> 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://sourceforge.net/mailarchive/forum.php?forum_name=snort-users
>
> Please visit http://blog.snort.org to stay current on all the latest
> Snort news!
------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, SlashDot.org! http://sdm.link/slashdot

_______________________________________________
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://sourceforge.net/mailarchive/forum.php?forum_name=snort-users

Please visit http://blog.snort.org to stay current on all the latest Snort news!