Snort mailing list archives
RE: heavily switched network questions
From: SRH-Lists <giermo () 333tech com>
Date: Wed, 31 Dec 2003 10:06:22 -0600
The best solution is to replace the current switches with ones that have port mirroring.Suppose I have a network consisting of a gateway which goes into a firewall. The connection from the firewall goes into a switch which leads to another level of switches. some of these machinesare servers,some are workstations. None of the switches have portmirroring (SPANports).
Actually this is not the only solution. This is a very commonly asked question, and I am sure that these answers can be found in the archive someplace. To sum it up, here are your options: Outside the firewall monitoring: 1) Put a hub between the firewall and the gateway. Pros: Cheap, easy. Cons: Adding a potential point on failure. Potential traffic bottleneck, but we are dealing with internet speeds here, so if your gateway is a T1, DSL, Cable, etc connection you will never see speeds approaching those that would cause a problem. 2) Put a switch with a span port between the firewall and gateway: Pros: More robust than #1 Cons: Point of failure. (but you can buy 2 and set up some sort of redundancy). More expensive than #1. Inside the Firewall: 1) Use a Tap on the Firewall to 1st switch connection Pros: The right way to do it. Very robust. Does not interfere with the traffic, so no added point of failure. Cons: Can be quite expensive, although they are coming down in price. You won't see server->server traffic. 2) Put a switch with a span port in place of the switch connected to the firewall. Pros: Fairly robust. Not as expensive as #1. Cons: Wont see server-server traffic if one of the servers is not on this switch. To see all server->server traffic, all switches would need span ports with snort monitoring them. 3) Put a hub between the firewall and the first switch: Pros: Cheap, easy. Cons: Traffic bottleneck, but again, we are dealing with internet traffic here, so it may not be a problem. No server->server traffic. Well, that should sum it up. -steve ------------------------------------------------------- This SF.net email is sponsored by: IBM Linux Tutorials. Become an expert in LINUX or just sharpen your skills. Sign up for IBM's Free Linux Tutorials. Learn everything from the bash shell to sys admin. Click now! http://ads.osdn.com/?ad_id=1278&alloc_id=3371&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:
- heavily switched network questions Stewart Larsen (Dec 30)
- Re: heavily switched network questions Josh Berry (Dec 31)
- <Possible follow-ups>
- Re: heavily switched network questions Josh Berry (Dec 30)
- RE: heavily switched network questions SRH-Lists (Dec 31)