IPsec VPN and NAT

At work we run a number of IPsec VPN tunnels to peers all over the world and we have always been concerned about possible RFC1918 address space collisions between our network and one of the other companies - it is surprising how often administrators keep the default 192.168.0.0/24 network! To the best of our knowledge on OpenBSD there was no good technical solution to the problem, and migrating the whole partner network to a unique address space is often politically unacceptable or too expensive.

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