Snort mailing list archives

Re: RE : Re: RE : Re: RE : Re: RE : overloaded system after upgrading


From: rmkml <rmkml () yahoo fr>
Date: Sun, 18 Dec 2011 19:00:03 +0100 (CET)

Hi Yossi,
I don't known if that help, but can you try with default snort.conf on 2.9.1.2 please? (comment profile_preprocs line, 
use ac-split on search-method...)
Do you have same performance pb with new v2.9.2 ?

What's snort rulesets you use please? (vrt? emerging? own?)
Can you check if you disable all rules: do you have drop ? cpu usage? (only preprocessor)
can you try with vrt ruleset only? drop? cpu?

Maybe you are right: 2.9.x are more cpu usage than 2.8.x but 29 introduce more cool feature: web gzip reply decode..., resolved bugs, preproc log, sdp/sip/pop/imap/ip/scada/gtp, paf...

stupid question: do you have enhanced bpf on your freebsd sysctl?
Regards
Rmkml


On Wed, 14 Dec 2011, rmkml () yahoo fr wrote:

Hi,Well, on your debug file, all versions drop packets:
2912: 8%
2861: 2%
Can you test with same rule please? (rule_file in snort.conf)
You Can "simplify" your bpf filters like this: ... and not host ( à.b.c.d or e.f.g.h or i.j.k.l ...)

Maybe interesting in your case split network traffic with pfring to multiples snort instance ? (or very simply with bpf)
Regards
Rmkml


a écrit :

     Hi Rmkml,

thanks again for your intention to help me :-)

To compare the result and the behavior of the old version with the new one I've run the to version parallel with the 
config files which I add to to this mail. I added also the outputs from both of the
them (see deb-log-XXX.txt)
 

again the as you can see in the screenshot (top.jpg) the process of the new version take more mem and overloaded the cpu

yossi



On 12/13/2011 07:46 PM, rmkml () yahoo fr wrote:
      It's not easy to find what's the pb without more information. Can you post your config?
Can you revert to old snort version: same pb?
Could you post snort verbose output statistic after 5mn running new and old versions ?
Do you have snort alerts with previous and new snort ? (+how many ?)
Do you have compiled old and new snort with exactly same options ?
Regards
Rmkml



a ֳ©crit :

     So,



On 12/13/2011 01:45 PM, rmkml () yahoo fr wrote:
      Hi, What is your previous Snort version please ?

my previous Snort version was 2.8.6.1

      Snort are on ids or ips/inline mode?

I use snort as ids with port mirroring

      It's a binary/rpm like or src code?

the snort I'm running is in binary form
      What is Snort options you have? Ipv6? ... (snort --help)

the only options I use are:
-i (interface)
--pid-path ./
-x
-D (or -v for debugging)
-c (conf file)
      Can you check if you disable all preproc or one by one please ?

I keep the preprocessors configuration and didn't changed them yet.
The only thing I have done was the relinking to the new folders.
      Regards
Rmkml 


a ײ³ֲ©crit :

      Hi Rmkml,

thanks for responding.
I walked step by step matching the old config file to the new snort version (running the snort after every step).
As soon as I changed the links of the dynamicpreprocessor and dynamicengine

-- old config --
dynamicpreprocessor file /usr/local/lib/snort/dynamicpreprocessor/libsf_ssl_preproc.so
dynamicengine /usr/local/lib/snort/dynamicengine/libsf_engine.so

--new config --
dynamicpreprocessor file /usr/local/snort_2.9.1.2/lib/snort/dynamicpreprocessor/libsf_ssl_preproc.so
dynamicengine /usr/local/snort_2.9.1.2/lib/snort/dynamicengine/libsf_engine.so

the machine goes wild; the memory and the cpu went high and a lot of packet were dropped.

Nothing else were changed or added.

I haven't been dealing with the daq yet! could it have something to do with it?!

tnx


yossi




On 12/12/2011 04:56 PM, rmkml () yahoo fr wrote:
      Hi Yossi, Maybe upgrade loss parameters like bpf filters ?
Could you send previous and new snort configs ?
Could you start old and new with verbose mode please ?
Regards
Rmkml



a ײ³ֲ©crit :

     Hi again

after having no response I thought that the following describe will help getting more information...
The preprocessors which I use are: frag3, stream5, prefmonitor, http_inspact, ssl

The memcap from frag3 and streem5 were reduced to less then 10% from the value which worked fine in the last version. 
AND a lot of packets are still been dropped. The cpu works on
100%.

I'd glad to have some help bringing my system back to the optimal performance.

tnx

yossi




-------- Original Message --------
Subject:
overloaded system after upgrading
Date:
Mon, 12 Dec 2011 12:03:33 +0200
From:
Yossi Asayag <yasayag () gmail com>
To:
snort-users () lists sourceforge net

Hallo there,

after upgrading my snort version into the new version 2.9.1. the machine is overloaded and drop a lot of entities even though Iײ²ֲ´v matched the new config file (inserted the values from the recent config file - which worked perfectly). Have someone an idea what could be the reason and how can I bring my system back to the optimal performance?

Thanks

Yoas
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