Check the link; instead of a 'cloud', there is a LAN. The router doesn't care about the IP of the destination, just that it can reach it and establish SAs. Follow the example and enter your IP's and it will work. Here's a link that is very helpful in troubleshooting VPNs.
If each of your routers only know to send the traffic for that subnet across the tunnel, then it will work, however, if both have the same connected subnets, then it won't work, as they know of those subnets locally. In that case you would have to NAT the traffic and encrypt it.
Table of ContentsIntroductionVersion HistoryPossible Future
UpdatesDocuments PurposeNAT Operation in ASA 8.3+ SectionsRule Types
Network Object NATTwice NAT / Manual NATRule Types used per SectionNAT
Types used with Twice NAT / Manual NAT and Network Obje...
Table of Contents Introduction:This document describes details on how
NAT-T works. Background: ESP encrypts all critical information,
encapsulating the entire inner TCP/UDP datagram within an ESP header.
ESP is an IP protocol in the same sense that TCP an...