I was testing a new backup solution that does replication across the wire to a secondary site. I didnt want to impact production, so I used VMware to clone the system I was backing up, and used an isolated network for my backup testing.
All was fine until I needed to setup a target at my second site, and still remain isolated. I needed to use a unique IP scheme, yet still have it routed across our WAN. All without having to nag the network team for my test environment.
Enter Vyatta router. Using it I was able to bridge my isolated network to the outside world, now I was able to download and install updates from the internet. I then found a post at http://www.arkf.net/blog/?p=231 that discussed using Vyatta as a site-to-site VPN. I followed through the steps and BAM, everything was connected.