Recently I have been getting ready for upgrades and deployments of vSphere 5.1/vCloud Suite 5.1 in my lab abd at client sites. I have used the ESX Deployment Appliance for several years and have had good luck with it. This time I ran into an issue that caused me to remove and reinstall the virtual nic on the EDA appliance. I noticed that the ifconfig output looked odd and remembered that I should make sure that /etc/udev/rules.d/70-persistent-net.rules doesn’t have any entries with “old” MAC addresses, particularly for “eth0.”

As I was troubleshooting the “network is unreachable” error, I did a search and found a reference to documentation I used to regularly provide to customers that were deploying Linux VM’s from templates…

Remove network configuration
The MAC address of the VM’s virtual nic is written into the udev persistent rules and needs to be cleaned out as the cloned vm will have a different MAC address.
/etc/udev/rules.d/70-persistent-net.rules
Remove entries containing “eth0”

It had been a while since I wrote that and I am glad I still had it.

As soon as I cleaned out the old entries and restarted the VM, the networking came to life and I am now back to work!