Has anyone else noted problems with the ethernet alias functionality in recent Linux kernels ? I've just done an update on my tunnel server (pogoplug E02 running Debian 8 with kernel 4.4.0-kirkwood) and within a day or so the 44net alias disappears. Nothing I can see in any of the logs. Replacing the alias via 'ip addr add 44.135.190.17/32 dev eth0:1' is enough to fix it, might have to hack into a cron job :-/R
Why are you still using ethernet aliases? This was originally a hack to be able to have multiple IP addresses on a single interface (using ifconfig) but since the introduction of the iproute2 package (which you apparently use, as it provides the "ip" command) this is really not required anymore. You can add addresses to eth0 without making an eth0:1 alias first.
Rob