Snort mailing list archives

Re: Snort multiple sensor configuration


From: Jack Pepper <pepperjack () afferentsecurity com>
Date: Thu, 09 Oct 2008 13:39:08 -0500

Quoting Matt Olney <molney () sourcefire com>:

Stephen,

As an aside, since you're using (I'm assuming SPAN or RSPAN) sessions on the
Cisco switches, make sure that you aren't dropping any packets at the swtich
port.  I've seen installations where they have oversubscribed their SPAN
ports and have lost packets there, rather than on the interface to the Snort
box.

Yes! excellent point.  This is a very common deployment error.  use  
mrtg or snmp to watch for dropped packets on the switchport that the  
sensor is plugged into.

for example, using a 10/100 port to monitor a switch with 48 ports, I  
can just about guarantee that snort will drop no packets at all.   
because it's only going to get one percent or less of the total traffic.

jp

-- 

Framework?  I don't need no stinking framework!

----------------------------------------------------------------
@fferent Security Labs:  Isolate/Insulate/Innovate  
http://www.afferentsecurity.com


-------------------------------------------------------------------------
This SF.Net email is sponsored by the Moblin Your Move Developer's challenge
Build the coolest Linux based applications with Moblin SDK & win great prizes
Grand prize is a trip for two to an Open Source event anywhere in the world
http://moblin-contest.org/redirect.php?banner_id=100&url=/
_______________________________________________
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: