Multiple physical locations, single subnet

[stumorc]

As bad as design as it sounds, I need to accomplish this. I have 2 physical locations. At each location I have a router and a switch. I need a single 24 bit private subnet on both switches. In other words, at location A, I need the subnet to be 10.1.1.0/24 and at location B, I need the subnet to be 10.1.1.0/24 also so that the devices at each location think that the devices at the other location are on the same subnet. I know this sounds crazy, and I know that all kinds of routing problems are sure to happen, but I need to accomplish this due to vendor requirements. Can L2TP somehow accomplish this? Would some form of NAT accomplish this? Any other ideas?

 

[burtsbees]

What vendor would require this, and why?!?!?!

Burt

 

[LawnBoy]

How many addresses do you need total? If it's less than 254, there's no problem... (and no routing).



"We must fall back upon the old axiom that when all other contingencies fail, whatever remains, however improbable, must be the truth." - Sherlock Holmes

 

[brianinms]

What type of connection do you have between the two locations? What vendor is dumb enough to require this?

 

[stumorc]

It's a telephone vendor (Nortel, implementing CS1000's). Less than 254 addresses is fine. It's going across a metro ethernet. The vendor's design is for redundancy and failover (the CS1000's have to be in the same subnet for the failover feature to work) and is intended for a campus network where layer 2 devices are at the customer/provider edge. That is where my problem has come in....we have layer 3 devices (routers of course) at the customer/provider edge. And that is where I am stumped.

 

[brianinms]

Why are they layer 3 if its metro E? Are you tagging a vlan along with an IP, or just an IP on an interface?

 

[stumorc]

We have multiple locations on Metro E with multiple subnets at each location. At some of the locations, we have several p-2-p T1's terminating there. Basically we have a hub and spoke setup with p-2-p T1's with the Metro E serving as the backbone between the "hubs".

 

[LawnBoy]

Can you:

1. set all the devices to the subnet you need.
2. configure a VPN between the routers.
3. Set some simple switches at each end to add the new subnet to whatever is feeding the routers.

Would this work?


"We must fall back upon the old axiom that when all other contingencies fail, whatever remains, however improbable, must be the truth." - Sherlock Holmes