Back-up VPN endpoints for a PIX - router question.

AM · Guest

I'm adding another endpoint for a IPsec tunnel on a PIX as an alternative.
The two enpoints belong to the same router connected to 2 different providers (one through serial cable and the other
one through an Ethernet interface).

The situation is the following

|---| |----------|---IP2(ethernet)-|------|
LAN1---|PIX|-------| internet | |router|---LAN2
|---| |----------|---IP1(serial)---|------|

I would like to forward all the traffic coming from LAN2 only through the serial link and to use the Ethernet one for
the VPNs. Moreover I'd like to guarantee that when the Ethernet link goes down (beyond that there is a transceiver
between the ethernet and the fiber optic) packets going to the PIX will forwarded using the serial line.
And when the link is established again, the router will use te old link. How can I do that?
I don't have an Autonomous System to use routing protocols.

All the endpoints I mentioned have a static IP address.

How can I implement the fact that when the ethernet link goes down the router will use the other link and if the PIX
"sees" that IP2 doesn't respond and uses IP1 the router will respond to packets coming from the serial link to the PIX?

Moreover when the Ethernet link comes up back, will the VPN be established using that link?

How to do that?

I shall really appreciate any of your suggestions, points of view, links...

Alex.