Comment 13 for bug 1463480

When machine-0 encountered this problem, it hadn't updated yet to 1.22, so it was still on 1.20.14.

Also, regarding the overwriting of the IP, I see in the log that the IP wasn't overwritten, but rather assigned multiple values, and juju status most likely just picked one to display (IIRC there was a bug not too long ago regarding the ordering of IPs displayed in juju status?):

2015-06-09 10:46:17 INFO juju.worker.machiner machiner.go:86 setting addresses for machine-0-lxc-0 to ["local-machine:127.0.0.1" "local-cloud:172.20.171.204" "local-cloud:172.20.168.104" "local-machine:::1" "fe80::216:3eff:fed6:252a"]

Going to pull in some folks with more networking knowledge to take a look.