by swass » Fri Sep 04, 2015 3:18 am
The issue is most likely that because the interface is brought down by way of the router being rebooted, similar to unplugging the cable, the address is lost. Dhcp would then attempt to get another address, but since the interface is down, it won't be able to get one. I had this happen too, but never bothered to pinpoint the actual root cause or a fix, as I have them plugged into an L3 switch off of my router. So even if I reboot it, the interface never actually goes down.