Snort mailing list archives
Re: Alert explanations
From: Martin Roesch <roesch () sourcefire com>
Date: Wed, 11 Aug 2004 16:39:39 -0400
Those are anomaly notifications coming from Snort's preprocessors, they're pretty self explanatory. "Possible retransmission" means that the stream reassembler thinks it has seen the packet before and is letting you know (this can be someone trying to evade the stream reassembler/IDS). "Overlapping fragment" messages are from the IP defragmenter, it's telling you that it's seeing fragments that overlap which is another anomaly and a possible indication that someone is trying to evade your IDS.
We should probably go through and document all the events that can be generated by the preprocessors one of these days...
-Marty On Aug 8, 2004, at 10:39 PM, Sean Brown wrote:
Over the past few days, I'm seeing a lot of 'Possible RETRANSMISSIONdetection' and 'Overlapping new fragment (probable fragroute)' showing up. I looked for a good explanation of what might be going on, but nothing really jumped out, so are there any good sites that I could go to to read up onthese things? Thanks -Sean Brown ------------------------------------------------------- This SF.Net email is sponsored by OSTG. Have you noticed the changes on Linux.com, ITManagersJournal and NewsForge in the past few weeks? Now,one more big change to announce. We are now OSTG- Open Source TechnologyGroup. Come see the changes on the new OSTG site. www.ostg.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
-- Martin Roesch - Founder/CTO, Sourcefire Inc. - (410)290-1616 Sourcefire: Intelligent Security Monitoring roesch () sourcefire com - http://www.sourcefire.com Snort: Open Source Network IDS - http://www.snort.org ------------------------------------------------------- SF.Net email is sponsored by Shop4tech.com-Lowest price on Blank Media 100pk Sonic DVD-R 4x for only $29 -100pk Sonic DVD+R for only $33 Save 50% off Retail on Ink & Toner - Free Shipping and Free Gift. http://www.shop4tech.com/z/Inkjet_Cartridges/9_108_r285 _______________________________________________ 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:
- Alert explanations Sean Brown (Aug 08)
- Re: Alert explanations Martin Roesch (Aug 11)