Let me preface this by saying I am not necessarily asking for someone to give me a total solution but for guidance to point me in the correct direction. I am experienced in Cisco products, just definitely not an expert. Here is what is needed:
We have two incoming network connections into our company. They are each have different IP blocks and we can not get both companies to work together on a solution and changing companies is not an option. We need to have a setup where when the primary link goes down, the secondary link takes over. The problem is the network setup is rather broken and thus we can not actually route through the cisco router but rather have to bridge the network connection. We also would like to have the cisco router dofirewalling at the same time. This switch over needs to be as transparent to the user’s as possible. The ideal solution for us would be if the network switches over, the IP addresses of the machines do not have to change. They are all on public IP addressing out of necessesity. It would be OK if when the network switched over to the secondary link to have the router create a NAT with the usual public IP’s from the first link being the private side of the public link. Any ideas on making this work would be greatly appreciated. We have two Cisco 3620 routers configured with three ethernet ports each and Cisco IOS 12.2 with the ENTERPRISE/FW/IDS PLUS IPSEC 3DES feature set on them. I doubt if we need both for this setup, but if required the second is available. If you need me to clarify anything further please let me know.
