I currently have two sites and both are outfitted with 1841 routers, two T-1s bonded through a Multilink interface. I want to setup a site to site VPN but can not get it to work. Is there a standard way of doing this. I tried to use the Multilink outside interface but it doesn't work because its IP address constantly changes. I am also NATing my private network across the Multi-link so my hosts can access the internet. Any assistance you could provide would be greatly appreciated.