A Cisco 888 router at a remote site is currently running with a DSL connection and a fixed IP on the DSL dialup, which is used for multiple VPN connections. In the course of a line upgrade, DSL will be replaced by a carrier ethernet connection, leading to a change in IP due to a transfer network being configured instead of the /32 IP. I can route the old IP to that router, but can not use it as primary IP on the WAN uplink. While I suppose putting it on a loopback interface would make the router reachable from the outside, outgoing VPNs would use the WAN interface's IP instead.
Is there any way to use the loopback IP for the IPSEC connections towards the other VPN locations?