IOS VPN with redundant routes

[simonw]

Hi,

I want to configure redundant paths for a 1761 router with ADSL and ISDN interfaces. I've been trying for a while to get a VPN site to site, then add in GRE tunnel. My question is this: has anyone managed to get this type of scenario in a single router working?

The major problem we've had has been the tunnel interface stopping inbound NAT to an inside SMTP server.

Thanks

Simon Wilson

[WILLIAM KLEIN]

I have done similar things on a single router. My suggestion would be to use GRE/IPSec tunnels so you can run a routing protocol like OSPF or EIGRP. Then use dialer watch or floating static routes to backup the ADSL interface.

[vcjones]

There is an example configuration in the "Redundant Routes in IPSec VPNs" white paper on my web site. The problem you describe sounds like an error in the access lists defining the traffic using the VPN. These access lists can be tricky because they depend upon where in the encapsulation process they are applied.

Good luck and have fun!

Vincent C Jones

www.networkingunlimited.com