Re: Check for NO TCP Flags set?

[MH <procana () insight rr com>]

Hi Paul,

What you are looking for is: flags:0
Snort already has a rule in scan.rules
It is listed as a SCAN NULL (sid:623)
Also, the stream4 preprocessor will detect this if it is enabled (it is 
enabled by default).
You can verify this in your snort.conf file.
Look for a line that in has:   preprocessor stream4: detect_scans

Hope this helps,
Mike



At 02:39 PM 5/9/2003 -0400, Sheahan, Paul wrote:

> I know I can check for flags set using Flags:S for example. Though I was
> curious if there is a way to check for NO flags being set?. I read that this
> may be seen in illicit servers.
>
> Thanks
> Paul
>
>
>
> -------------------------------------------------------
> Enterprise Linux Forum Conference & Expo, June 4-6, 2003, Santa Clara
> The only event dedicated to issues related to Linux enterprise solutions
> www.enterpriselinuxforum.com
>
> _______________________________________________
> 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



-------------------------------------------------------
Enterprise Linux Forum Conference & Expo, June 4-6, 2003, Santa Clara
The only event dedicated to issues related to Linux enterprise solutions
www.enterpriselinuxforum.com

_______________________________________________
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