A question I hope some one can help with.
Can anyone explain when I terminate a tunnel on the concentrator using a DHCP address which is in the same network as the private interface it fails?
All VPN clients are fine, but when I look at the SA on the router, it encrypts all packets but never gets a return from the concentrator SA, if you look at the SA on the concentrator the return traffic is decrypted and encrypted but never makes it back across the tunnel.
However if I use another network, and use the concentrator as a Stub router all is good, looking at the IOS configs everyone's using a different subnet, which is fine. But why is this the case? Can't work it out in my head.