I have an Pix 515E with 6 interfaces.
One of the interfaces has a T-1 router connected to it, and has the public IP x.x.x.x
One of the interfaces has another T-1 router connected to it (from another ISP) and has the public IP y.y.y.y
I have a remote location with a single T-1 and a ASA 5520, the ASA has public IP z.z.z.z
How can I specify 2 VPN tunnels for the same destination networks between the PIX & ASA, so that the VPN tunnel would fail over if one of the T-1s on the Pix decide to fail?