Route incoming request to 127.0.0.1?

I remember hearing / reading that it's possible to route incoming requests from a specific IP to 127.0.0.1 to minimize the effects of 'hammering' on your server. -Am I remembering correctly or can someone perhaps point me in the right direction?

The actual issue is that I have some moron of a spammer hammering the living heck out of my Win2K server with attmepts to deliver spam. Hammering to the point that my mail server (TNSoft's mail server) is peaking at 90% CPU from time to time.

The requests are all coming from 1 of 3 IP's (blocked) but the resource usage is unacceptably high. I had read that routing requests from xxx.xxx.xxx IP(s) to 127.0.0.1 could help, but I'm afraid I have no idea of how to do this (if, in fact, the assumption is correct).

Thanks in advance for any help on this one!

what do you mean they are blocked? You should be blocking this from your firewall not the server (this is also why you dont use a server with software firewall). If you dont have a firewall at the router put an ACL in there that blocks those three address' from coming in or you can route them to null0. basicly you are under a DOS attack, and can call your ISP and have that blocked from there also.

Thanks for the reply juniperr,

Unfortunately this is on a box colocated with an ISP who doesn't provide much in the way of firewalls, etc... I agree that best practices say to put the workload of filtering on something other than the server but in this instance it's not an option I have available.

The 'blocking' that's taking place at this point is all on the mail-server side, using it's built in anti-spam features. While they work fine for refusing connections from a few IP's - or even a lot of IP's under a light load with ocassional requests - they're not coping well with a high amount of hammering. -Hence my hope for another solution (like redirecting all request from IP xxx.xxx.xxx.xxx:110/25 to 127.0.0.1 - in other words, "right-back-at-ya".