The following email went out to all those that have a private IP assigned:

We had previously recommended that private IPs be configured on eth1, however we are going to remove this interface from service. If you are taking advantage of our private network you must ensure your private IP is now configured as an alias on eth0. You can find detailed documentation to assist you in the transition here:

http://www.linode.com/wiki/index.php/Co ... Static_IPs

Please complete the configuration changes by March 15th, 2009. Rebooting is not required (either before or after the move). After this date your Linode will no longer be able to send or receive traffic over eth1.

If you require assistance or have any other questions or concerns please contact us by opening a support ticket or feel free to post a reply here.

-Chris

Just as well I spotted that in my RSS feed - clients wouldn't have been happy if networking had just disappeared!

I don't do any private networking but, for some obscure reason, both my Gentoo Linodes are working on eth1 only.

Just went into my non-production server to look at doing the reconfiguration, simply changing everything that said eth1 to eth0.

Stopped eth1, started eth0, no joy. No such device, something about kernel modules.

So, have a look at what config was set for eth1 by doing:
grep -r eth1 /etc

Turns out that the problem was in /etc/udev/rules.d/70-persistent-net.rules

# net device (uml-netdev)
SUBSYSTEM=="net", DRIVERS=="?*", ATTRS{address}=="fe:fd:REDACTED1", NAME="eth0"

# net device (uml-netdev)
SUBSYSTEM=="net", DRIVERS=="?*", ATTRS{address}=="fe:fd:REDACTED2", NAME="eth1"

Any clues as to why I had those two MAC addresses assigned and the ones for eth0 were/are wrong?

By commenting out the entry for eth0 and changing the 1 in eth1 to 0 and rebooting, all was well.

I assume the same will be the case for the production server which gets done early Saturday morning - but why?

(BTW - I put the REDACTED in - that wasn't what was in the file!)

Ever migrated across DCs, or changed primary IPs? If so, your MAC address changed, and udev, being oh-so-useful, renamed your new eth device...

-Chris

I've added IPs for extra SSL virtual hosts - I didn't know that this had changed my primary, but guess it did.

I have yet to discover anything udev is good for apart from causing weird bugs and being generally annoying.