We have a Zimbra mail server at work running on top of a 64bit Ubuntu 8.0.4 OS. The computer is a Dell Precision 380 and after a power outage last night, (yes it is connected to a UPS) the motherboard got fried. Luckly, I have another Precision 380 I could swap all the drives, memory and network interfaces to. When I booted up, all went as planned until I realized that my internal network card eth0 was not found. Eth0 is an on-board card, so I new it was working but Ubuntu was not finding it. I ifconfig’ed to check for eth1, eth2, eth3…etc…finally I found it…it was not eth4…weird, I thought. So then I went to /etc/network/interfaces to change eth0 to eth4 and all would be well. Correct? Not so fast. I could not get eth4 to come up with the static ipaddress that is listed in /etc/network/interfaces. What the heck…..did some more digging and found a udev rule that ties the mac address to the network card. So I had to edit the udev rule to reflect the new mac address of eth0 and then restart the udev service and what do you know…eth0 came up again. Awesome!
Rule to edit:
eth0 was the first defined rule and all thast was needed was to modify the mac address to reflect the onboard nic in the new computer.