I'm setting up a VPN between (2) offices that both use cable modems. One side is a static IP and the other is dynamic. On the dynamic side, the office is using a Linksys router to do NAT. How do I configure the RouteFinder with the Linksys router?

It is best you take out the Linksys NAT router, our RF550VPN can function as a NAT router and a VPN router at the same time.

If you must keep the linksys NAT router, here is a document which shows how to setup RF550VPN behind a NAT box.

http://www.multitech.com/en_US/DOCUMENTS/Families/RouteFinder_SOHO/manuals