Re: Snort rule question

[Matt Kettler <mkettler () evi-inc com>]

At 06:37 AM 6/26/2003 -0600, James Lay wrote:
> alert tcp $SMTP_SERVERS 25 -> $EXTERNAL_NET any (msg:"Open Mail Relay 
> Attempt"; content:"Relay access denied"; classtype:mail-abuse; 
> sid:1000001; rev:1;)
>
> Now the above rule works.  I originally had:
>
> alert tcp $EXTERNAL_NET any <- $SMTP_SERVERS 25 (msg:"Open Mail Relay 
> Attempt"; content:"Relay access denied"; classtype:mail-abuse; 
> sid:1000001; rev:1;)
>
> And it did not work.  Any reason the two aren't equivalent?

Because <- is invalid.

See http://www.snort.org/docs/writing_rules/chap2.html#tth_sEc2.2.5

"Also, note that there is no <- operator. In snort versions before 1.8.7, 
the direction operator did not have proper error checking and many people 
used an invalid token. The reason the <- does not exist is so that rules 
always read consistently. "




-------------------------------------------------------
This SF.Net email is sponsored by: INetU
Attention Web Developers & Consultants: Become An INetU Hosting Partner.
Refer Dedicated Servers. We Manage Them. You Get 10% Monthly Commission!
INetU Dedicated Managed Hosting http://www.inetu.net/partner/index.php
_______________________________________________
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