Help! Multihoming not working

romeoalvarez · ‎10-27-2004

I have 2 offices connected by a T-1 line. One office is unable to receive internet service, so i set up a NAT from one office to the other to allow for internet service to reach the non-internet office. The systems works great, Road Runner ISP provides service to both offices through the NAT. This week QWest DSL is able to provide the non-internet office with DSL Service. I was told i could enable "multihoming" to have 2 ISPs. Can anyone tell me what i would need to do to enable this with my current situation. will i have to reconfigure my routers, 2650 series? I have seen the white paper on this, but it isn't specific as to whether NAT is being implemented for the first time.

klouthan · ‎10-27-2004

Hmm, it would be easier if you had a 2651 with two ethernets instead of just one.

klouthan · ‎10-27-2004

What are you currently doing NAT on?

klouthan · ‎10-27-2004

I would connect a DSL router to the modems at both sites and run RIP on both DSL routers and both 2650 routers. If you only have two sites RIP wont be a problem. I would let both DSL routers (like a linksys befsr41 or something cheap like that) do nat and hand out DHCP addresses for their respective sites. This way site 1 uses site 1's internet connection and site 2 uses site 2's internet connection. Not a very good solution, but that is the best I could do with limited info.

romeoalvarez · ‎10-28-2004

Thanks for the response. Let me explain further.

I have to buildings 50 miles apart. I have a T-1 connecting them. Building A is able to receive internet service, building B isn't. So i set up a NAT to feed service from building A to building B, the ISP is Road Runner. Each site has a cisco 2650 router with NAT configured into them so that they can network and share files. Now, QWest has expanded far enough to allow building B to receive DSL service. What i want to do is, keep road runner at buuilding A and at building B have QWest DSL. To do this i was told i should configure the routers to "multihome with auto injection". So my question is, do i need to completly reconfigure my routers to do this or since NAT is already set-up can i just plug in my DSL line.