Snort mailing list archives
Re: Packet Performance Monitor
From: Russ <rucombs () cisco com>
Date: Mon, 26 Sep 2016 08:57:19 -0400
Hey Mike,This has been a "feature" of Snort for quite a while and likely will only be fixed in Snort++, which inherited the issue. It arose when we added a performance feature to compile all the rules that share a fast pattern match end state into a single tree that can be evaluated more quickly than iterating over the individual rules. Such rules tend to have a lot in common and the common part is evaluated just once. Consequently, when the tree triggers a latency event, it could be one or more rules that are at fault. I'm thinking we will add a mapping and report the index that can be used to find the rules. This is in our backlog.
Thanks Russ On 9/26/16 8:27 AM, Mike Cox wrote:
Perhaps snort-sigs was the wrong place to post this. Removing them and adding snort-devel.Thanks. Mike CoxOn Thu, Sep 22, 2016 at 10:59 AM, Mike Cox <mike.cox52 () gmail com <mailto:mike.cox52 () gmail com>> wrote:I've been messing around with the Packet Performance Monitor (PPM) preprocessor and it seem like a nice capability of Snort. However, when I configure it to suspend/disable expensive rules once the thresholds are reached, how do I know which rule was suspended? I see it generates the GID 134 alert along with the packet it was considering at the time but I need to be able to know what rule was suspended so I can: 1) account for and correlate the coverage gap (if necessary) 2) tune the rule Thanks! Mike Cox ------------------------------------------------------------------------------ _______________________________________________ Snort-devel mailing list Snort-devel () lists sourceforge net https://lists.sourceforge.net/lists/listinfo/snort-devel Archive: http://sourceforge.net/mailarchive/forum.php?forum_name=snort-devel Please visit http://blog.snort.org for the latest news about Snort!
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Current thread:
- Packet Performance Monitor Mike Cox (Sep 22)
- <Possible follow-ups>
- Packet Performance Monitor Mike Cox (Sep 26)
- Re: Packet Performance Monitor Russ (Sep 26)