Cisco 2801 failover help

[Erosional]

We have a Cisco 2801 Router that currently routes a number of internal networks out via one interface onto an SDSL router and then onto the internet. It is configured to run NAT and there are a number of Static IP mappings between given external addresses (associated with the ADSL accounts) to specific servers on the internal networks.

We would like to set up a new ADSL line to act as a backup in the event of the SDSL failing. However any new ADSL account will obviously come with a new set of external IP addresses.

Is there anyway to configure the CISCO router to allow for some form of automatic failover that can also handle the new IP address without breaking the NAT translation tables?

 

[echang15]

Route-maps and NAT. It took me a few weeks of asking everyone and playing with it myself, but I finally got it.

Sample:


interface fastethernet0
blah
interface fastethernet1
backup interface fastethernet0

ip nat inside source route-map DSL1 interface fastethernet0 overload
ip nat inside source route-map DSL2 interface fastethernet1 overload

access-list 40 permit 192.168.0.1 0.0.0.255 ;nattable addresses

route-map DSL1 permit 10
match ip address 40
match interface fastethernet0

route-map DSL2 permit 10
match ip addrewss 40
match interface fastethernet1

hope this helps!

 

[Erosional]

Hi echang15

Thanks for the quick response. Will certainly give your suggestion a try as we need to get it resolved on Monday....but as the deadline is so close I really need to have a plan B, C & D........just in case.

I am sure you will agree that would be a prudent plan......though I hope your way does solve our problem as it's so much easier to get it right with plan A.

So does anyone else have any other suggestions?

 

[echang15]

That's the setup im currently using for our 15+ person network. We are NATing address both from the T1 and the DSL connections, and have setup dual static IPs for servers/etc.

let me know if you need more details.