Snort mailing list archives
RE: snort dropping 48%
From: "Sheahan, Paul" <Paul.Sheahan () priceline com>
Date: Thu, 6 May 2004 14:02:59 -0400
I still don't have an answer either. 49% of packets being dropped is absolutely ridiculous. I recently ran TOP to check memory while Snort was running my content-based rules and noticed that even though I had 1 gig of ram in my server, there was almost no free memory. So I upgraded to 4 gig of RAM figuring Snort just needed more RAM, but the same problem is still occurring, 49% of packets are still being dropped. Should I take a look at libpcap? I understand there are multiple versions. What version should I be running? Thanks -----Original Message----- From: snort user [mailto:snortuser () hotmail com] Sent: Wednesday, May 05, 2004 1:42 PM To: Sheahan, Paul Subject: RE: [Snort-users] snort dropping 48% Im actually getting the same problem on a Debian machine. When the traffic exceeds 100Mb/s snort really starts dropping packets fast. If I remove content based rules then dropped apckets significantly drop. I never saw a reply other than it could be a RedHat problem so I was wondering if anyone else had any ideas since I am not on RedHat.
From: "Sheahan, Paul" <Paul.Sheahan () priceline com> To: <snort-users () lists sourceforge net> Subject: [Snort-users] snort dropping 48% Date: Wed, 28 Apr 2004 13:46:55 -0400 Can anyone give me a tip in this situation? I used to have a Snort 1.9 sensor running on RHLinux7 on a 100mb Ethernet network. On that sensor I ran the most of the default rules plus my own custom rule file, which contained a lot of content-based rules. It handled it no problem and didn't drop any packets. Now I've upgraded to a big beefy server, gig Ethernet, RH Linux 8.0 and Snort 2.0.5 using the same Snort config as above. Traffic levels are
the
same. Now I noticed it was dropping half of the traffic! My custom content rules are extremely important to me, so I performed a test. I created this bare bones snort.conf which basically disables all
standard
rules and extra preprocessors: var HOME_NET [10.10.0.0/16] var EXTERNAL_NET !$HOME_NET preprocessor frag2 preprocessor http_decode: 80 unicode iis_alt_unicode double_encode iis_flip_slash full_whitespace include classification.config include reference.config include /etc/snort/my.rules include /etc/snort/pass.rules Then I started Snort and let it capture traffic for a while. I stopped Snort and it is STILL dropping 48% of the traffic! My "my.rules" file contains a few hundred content-based rules. What gives? Can Snort no longer handle content-based rules? Or am I missing something here? Thanks, Paul
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Current thread:
- snort dropping 48% Sheahan, Paul (Apr 28)
- Message not available
- Re: snort dropping 48% Matt Kettler (Apr 28)
- legit network-traffic generating tool? siddharth thakkar (Apr 28)
- Re: snort dropping 48% Matt Kettler (Apr 28)
- Message not available
- <Possible follow-ups>
- RE: snort dropping 48% Sheahan, Paul (May 06)
- Re: snort dropping 48% sgt_b (May 06)
- RE: snort dropping 48% Sheahan, Paul (May 06)
- Re: snort dropping 48% sgt_b (May 06)
- RE: snort dropping 48% Sheahan, Paul (May 06)
- RE: snort dropping 48% Frank Knobbe (May 06)
- Re: snort dropping 48% sgt_b (May 06)
- Re: snort dropping 48% Josh Berry (May 07)
- RE: snort dropping 48% Chuck Holley (May 07)
- RE: snort dropping 48% Michael Boman (May 10)
- Message not available
- RE: snort dropping 48% Josh Berry (May 07)