EH-Net

Good day all,
  I'm looking for some information on setting up several IDS's on our network.  I'm looking for the best system (pc) to run some version of linux to run snort on.  We prefer dell but I'm sure I could convince my boss to use something else.  I realize this is probably isn't really even a good question since it's probably the NIC that's more important the the PC itself. 

  One other question is a network tap.  I've made the network tap that snort has on their website but i'm not sure how to get the full duplex off of it.  If you look at it you have to jacks for the two pair you are using to get the info off of.  Does that me I will have to use 2 Nic's and if so how does it get combined back into one signal.  Or do I have to basically run snort and just use some sort of filtering on it.

  We also looked at some Commercial taps but my boss isn't to keen on it, he is feels we should us as much open source and free material as we can get our hands on.

  Any websites referencing this info would be greatly appreciated.

humv

Hardware-wise, I wouldn't be too concerned unless you have a truly enormous amount of traffic going over your network. Most any recent machine with a decent amount of ram should suffice for running snort inline.

The DIY tap on the snort site will require two intrfaces to listen to the entirety of the traffic. You can use trunking software, as they mention, to put everything back together, but you would still need both interfaces to get it in the first place.