Ubuntu 12.04 Network Connection Issue

Recently we ran into a very bizarre issue with a new VM Ubuntu Server 12.04 image and assigning a static address.

Using DHCP, the image was completely fine and could complete ping and wget any website on the Internet. When we switched it over to a static ip, we ran into a really puzzling situation. We could ping and SSH to other machines on the Internet, but could not wget any webpage. It would just say “connecting” and never get the webpage. Apt-get and likewise tools would not connect either. Everything was accessible on the local LAN though, which was very puzzling.

We spent hours going over the new network configuration. Checked all of the route/bridge setting possible. Every time we moved it back to DHCP, it would work fine.

On a whim, we assigned it another free IP static LAN address that had NEVER been used on the network. Voila, everything started working again! We had found that we had spun up a VM a few hours earlier that had utilized the same static IP that we had tried. Even after that old VM had been shutdown, somehow that routing “stuck” in either our switches and/or firewall appliance. Traffic would go out from our new VM, but was never delivered back to it correctly, hence our weird webpage requests.

Moral of the story, always try using a fresh static IP!

We hope this helps someone else!