I am presently running several websites and a mail server from my home network. I have a business DSL account with 8 public IP addresses (1 by itself, and 7 in a block). To handle routing/firewall/gateway, I am presently using RRAS, DNS, & DHCP from Windows 2003 running on a ancient (circa 2001) PC -- which I suspect is going to fail any time now.
What I would like to do is replace that with a simple router. Have a consumer model LinkSys Wifi-router, which I'm presently just using as an access point (don't have the model number handy, but it's one of their standard models). It seems to be able to handle all the NAT/firewall/DHCP tasks -- except for handling routing the multiple public addresses. (e.g., I need x.x.x.123, port 21 getting to one machine, but port 80 of x.x.x.123 & x.x.x.124 to going to another, and x.x.x.123, port 5000 to still another etc).
So my questions are:
This can't be done on a Linksys router with stock firmware. It can be done if you load a third-party firmware, but there's no GUI (afaik) to accomplish it, so you'll be hacking system shell scripts which is pretty hairy. I would recommend getting a low-power or older PC and installing PFSense.
PFSense is an open-source router appliance OS distribution with a very easy to use web front end.