[Snort-users] 2.1.3rc1 Performance

Gary_Portnoy at ...11307... Gary_Portnoy at ...11307...
Wed May 19 07:50:28 EDT 2004

The rules were the same, i just changed the link to the snort binary, so 
that's not it. 

Did pcre get rewritten, because it's been supported for a while now??? 
As for the libpcap question, i'll try to find out, because someone else 
compiled the 2.1.1 binary on a different machine.  But the 2.1.3rc1 that I 
compiled, libpcap is the most recent version 0.8.3.  In fact, i can almost 
quarantee that it was a different version since 0.8.3 was released on 
March 30 and I've had the 2.1.1 binary since before then.  But shouldn't 
the newer version of libpcap be faster and more efficient?

Gary Portnoy

Dirk Geschke <Dirk_Geschke at ...1344...>
05/19/2004 10:32 AM

        To:     Gary_Portnoy at ...11307...
        cc:     snort-users at lists.sourceforge.net, Dirk_Geschke at ...1344...
        Subject:        Re: [Snort-users] 2.1.3rc1 Performance

Hi Gary,

> Yesterday I replaced my 2.1.1RC1 build with 2.1.3RC1.  Today I checked 
> perfmon stats and nearly fell off my chair.  They are reporting that 
> is dropping on average about 15% of traffic.  With 2.1.1RC1 perfmon has 
> always reported 0% pkts dropped and I believed it.  Now I am seeing that 

> there are times when snort is dropping as much as 89%, and that is at 
> times with only 0.9mbps throughput and using 11% of the cpu.  Some other 

> times i am seeing drop rates of 12% with 5.1mbps throughput while using 
> 77% of the cpu.

did you use the same rules on both versions? There are a lot of changes
between these two versions especially an increase in the use of pcre...

And did you also use the same libpcap?

Best regards


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