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New Member

Forwarding traffic based on new destination ip address


This issue I am running into is this.

We have two offices, the data center in one office, and a corp. office in another state.

We have a direct T1 between us from their internal to our internal.

Currently clients use the public ip for the data center office for services we provide.

Each office has a T1 to the net. What we want to do is if OUR T1 goes down, to inform clients to point to another ip (one of the corp offices public ip's) which would hit their (the corp office) external ip, be NAT'd to an internal (just depending on what we give them). And then that internal would be a 2600 series router. I want to it to then take the packet and change the destination to OUR (DC office) internal ip which the router already has a route through the T1 to.

So if our net goes down, we can give them another ip which will hit the corp office, and then traverse the T1 between us.

I already have connectivity between our two networks via the T1, but is there a protocol or something on a 2600 series that can take all the traffic and change it so the new destination is our network.

Otherwise the client sends the packet, and the packet hits the external ip ----> goes through NAT ---> becomes an internal ip and stops because it has reached its destination.

Any help would be much appreciated!

  • WAN Routing and Switching
New Member

Re: Forwarding traffic based on new destination ip address

New Member

Re: Forwarding traffic based on new destination ip address

Thank you for the reply :). Not really, it wouldn't be too difficult to have the router actually route two different paths to the same ip depending on some sort of stateful situation.

The issue is that I need the router to actually ALWAYS forward traffic sent to it on an ip/int to a different subnet.

So say for example we have a Firewall interface. The interface is a public 68.x.x.x which translates to 10.200.x.x internally. That 10.200.x.x is the ethernet interface on a router. I want to then forward any traffic revieved on this interface to 10.20.x.x out another interface. The route to 10.20.x.x isn't the hard part, its getting the router to listen to traffic and change the destination IP of the packet it receives and then forward it on.

New Member

Re: Forwarding traffic based on new destination ip address

I would imagine you could set up a route map to successfully accomplish what you want to. Try that.


New Member

Re: Forwarding traffic based on new destination ip address

Thank you for the reply again. :).

I would imagine I could setup a route-map to forward traffic received on the one interface out the other, but wouldn't the destination ip in the packet still be the original network? So it will forward out the interface I set the route map too, but then will be like "Hrmm, now where do I go since my destination is still 10.200.x.x.......oh yea back through the interface I came in on"