Here is a just of what I'm trying to do in this diagram below.  In the diagram the firewall appliance is the Cisco 1751 I have:



Basically I have 2 web servers that use ftp, web, and ssl ports.  They are identical and use ms loadbalancing.  Not my idea but I need to make it work.  There are 2 domains housed on the servers.  Currently I have one cabletron which uses NAT and forwards ports 80/21/443 off its external interface to the load balanced ip on the ms IIS servers.  The problem I have is the verisign certificates for each domain must be bound to separate public ip addresses.  So right now only one is being used, I can only bind one ip address to the external interface, which is the x.x.x.116 in the example.  I have a Cisco 1751 router with 2 ethernet interfaces which I want to replace the cabletron with.  How do I bind another ip address to an interface, and how would I route traffic back through the ip address it came in on.  What rules do I need to setup to forward traffic coming into the external interfaces (x.x.x.116, x.x.x.114) to the load balanced ip (172.16.0.10)

If I can clarify anything please reply if anything is confusing.  Some of the features in the IOS I'm still trying to figure out.

The IP addresses on the Cisco 1751 router's Ethernet interfaces will need to belong in seperate broadcast domains. You possibily could subnet the existing LAN and then configure the addressing scheme coming in from the Public network.  Once you establish the One-to-One Nating, the router should keep track of the IP sessions taking place.