Snort mailing list archives
RE: Low Snort performances
From: "Bob Walder" <bwalder () spamcop net>
Date: Mon, 19 Apr 2004 12:40:22 +0200
Hi, In our most recent IDS tests (www.nss.co.uk/ids) we went way beyond the traffic levels you are seeing here with no dropped packets whatsoever, and we hit the sensor with some pretty tough background traffic that you would not expect to see in a real network, as well as using lots of "real world" scenarios. We were using a dual P4 box with a server-class chipset, 2GB RAM and Intel NICs. But I would venture to suggest that the specification you outline below should be capable of handling 50Mbps with no problems, no matter how many Snort rules you have enabled At the risk of starting another OS war, I can say that one of the main differences between our test rig and your sensor is that we used FreeBSD for the underlying OS. We have tried installing Snort on Linux before and noted a 500% performance hike when we moved to BSD on the same platform. This was under an older kernel and without all that fancy ring buffering PCAP stuff, but the results were enough to make us switch permanently from Linux to BSD for our Snort sensors, and we have never gone back to check difference with later versions. Remember, I am not taking a pop at Red Hat or Linux here - just stating facts. The other major difference between our test rig and yours is the NICs and underlying network plumbing, of course - another potential bottleneck. Although I have seen good results form SysKonnect cards before (we generally use Intel ourselves), we were using copper Ethernet infrastructure and not FDDI Token Ring - perhaps there is an issue with the cards and/or their Red Hat Linux drivers? I would start by looking to update the drivers (are you using SysKonnect drivers or those that are auto-installed by the OS?) - then maybe try different NICs if that is possible. After that, you could try switching to BSD if you are so inclined. But in general, your sensor spec looks OK and there is not TOO much tuning you can do in terms of Snort or disabling OS services (you should disable everything you don't use, anyway) that is likely to make the kind of difference you are looking for Regards, Bob Walder Director The NSS Group
-----Original Message----- From: snort-users-admin () lists sourceforge net [mailto:snort-users-admin () lists sourceforge net] On Behalf Of Gianluca Murgia Sent: 19 April 2004 11:02 To: snort-users () lists sourceforge net Subject: [Snort-users] Low Snort performances Hi, I'm using snort 2.1 with a Dual Intel P3 1266MHz 2GB RAM, OS Redhat 7.3 ( kernel 2.4.18-3smp ). I use it to monitor the traffic on a fddi token ring network. The traffic can be up to 50MB/s and the network cards are SysKonnect SK-5844 10/100 Mb/s. The snort config file is set to reassemble the packets. The maximum rate I can sniff without loss of packets is up to 4Mb/s. What's the problem? Is there any kind of important setting on the machine that is missing? On the other hand, which settings or services must not be running on the machine in order to improve the performances? Thanks, Luca ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________ 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/sno>> rt-usersSnort-users list archive: http://www.geocrawler.com/redir-sf.php3?list=snort-users
------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________ 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:
- Low Snort performances Gianluca Murgia (Apr 19)
- Re: Low Snort performances Edin Dizdarevic (Apr 19)
- Re: Low Snort performances Chris Green (Apr 20)
- <Possible follow-ups>
- RE: Low Snort performances Bob Walder (Apr 19)
- RE: Low Snort performances todb (Apr 19)
- Re: Low Snort performances Nicholas Brawn (Apr 28)
- RE: Low Snort performances Bob Walder (Apr 19)
- RE: Low Snort performances todb (Apr 19)
- RE: Low Snort performances Richard Bejtlich (Apr 19)
- RE: Low Snort performances Zphosis De Extrodinaire (Apr 20)
- RE: Low Snort performances SN ORT (Apr 19)