Here's my problem. I used to have two routers connect via T1. To back up the T1, I had a tunnel running between the two routers on their Internet-facing ethernet ports. This worked fine; if the T1 went down, traffic automatically routed across the tunnel, and the two sites stayed connected.
Recent I added a third site, with a T1 between it and my first site. I wanted to create a backup tunnel, just like I did before, but now I learn that the ethernet port on my first site's router can only be configured with a single tunnel (using the crypto map command). So apparently I can have only one tunnel assigned to this interface.
What to do? Can I use subinterfaces on my first site's Internet- facing ethernet port? If I do that, that's really going to screw up my IP addressing scheme. Or is there a way to assign two crypto maps to a router's interface, and I just don't know what it is?
Thanks.