Snort mailing list archives
Re: Drifting timestamps
From: Martin Roesch <roesch () sourcefire com>
Date: Thu, 21 Oct 2004 11:53:14 -0400
Hi Jacob,It could be but IIRC Barnyard is just reading the timestamps from the unified files for its insertions. I just checked the code and Barnyard's ACID database plugin gets timestamps from the unified file. Might be MySQL, but that would be weird...
-Marty On Oct 18, 2004, at 3:18 PM, Jacob Roberts wrote:
We check the timezones and clocks of all the systems involved. They areall correct and don't drift from day to day. They daily routine is to Stop barnyard, stop snort, drop the Mysql database(not just deleted the records), re-create the database, start snort, start barnyard. At the time everything is restarted the timestamps are in sync with correct time. As the system runs the timestamps drift We've narrowed it down to on of the following: 1. Something weird in Snort (probably not) 2. Something in Barnyard (we've no idea) 3. Something in Mysql. (We've added a timestamp column to the event table and it auto-inserted correct timestamps. So we don't thing its Mysql) Could this be a Barnyard thing? -----Original Message----- From: Martin Roesch [mailto:roesch () sourcefire com] Sent: Sunday, October 17, 2004 9:10 AM To: Jacob Roberts Cc: snort-users () lists sourceforge net Subject: Re: [Snort-users] Drifting timestamps Hi Jake, That'd have to be the system clock on the sensor drifting, the timestamps that Snort uses is based on a call to gettimeofday() that libpcap performs when it receives a new packet. Snort has no internal time tracking mechanisms and in fact we take advantage of the fact that libpcap gives us time data "for free" to track time inside Snort. -Marty On Oct 15, 2004, at 6:50 PM, Jacob Roberts wrote:We have a snort setup with barnyard which dumps in to a MySQL database. We stop snort and barnyard each day, delete the database, re-create it, then restart snort and barnyard. As snort runs through the day we start to see the timestamps of alertsdrift behind actual time. We aren't receiving an excessive amount of alerts so we ruled out Barnyard not being able to keep up with the alerts generated by Snort (I don't know if that would happen anyways) Has anyone had anything like this happen? We haven't been able to track it down and aren't sure what to do. Thanks, Jake Roberts Brigham Young University jake_roberts () byu edu ------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Giveus Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find outmore http://productguide.itmanagersjournal.com/guidepromo.tmpl _______________________________________________ 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-- Martin Roesch - Founder/CTO, Sourcefire Inc. - +1-410-290-1616 Sourcefire - Discover. Determine. Defend. roesch () sourcefire com - http://www.sourcefire.com Snort: Open Source Network IDS - http://www.snort.org
-- Martin Roesch - Founder/CTO, Sourcefire Inc. - +1-410-290-1616 Sourcefire - Discover. Determine. Defend. roesch () sourcefire com - http://www.sourcefire.com Snort: Open Source Network IDS - http://www.snort.org ------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on ITManagersJournal Use IT products in your business? Tell us what you think of them. Give us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more http://productguide.itmanagersjournal.com/guidepromo.tmpl _______________________________________________ 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:
- Drifting timestamps Jacob Roberts (Oct 15)
- Re: Drifting timestamps Martin Roesch (Oct 17)
- <Possible follow-ups>
- RE: Drifting timestamps Jacob Roberts (Oct 18)
- Re: Drifting timestamps Martin Roesch (Oct 21)
- RE: Drifting timestamps M. Shirk (Oct 20)
- RE: Drifting timestamps Jacob Roberts (Oct 21)
- Re: Drifting timestamps M. Shirk (Oct 21)