I am using arch linux arm on a Raspberry Pi for an embedded application. I have one machine which was set up around a year ago which works excellently, it does not get updated and is still on a 3.18.7 kernel. Just recently I have set up a new machine with a fresh install of arch and the latest kernel 4.4.15, this new device is not correctly setting the nameserver and cant resolve host names. The hardware for both of these machines is identical. Note this is in a commercial environment and I am behind a very restrictive proxy, however both machines are connected to the same wireless network and as far as I can see are set up the same, but something is not working on the new machine.
I have checked everything I know how to check, and cannot find anything wrong. I am hoping someone might be able to point me in the right direction for more things to test to try and narrow this problem down.
IP addresses are assigned by DHCP, on the working machine something (is it dhcpcd?) is finding the correct nameserver and entering into /etc/resolv.conf on the non working machine this is not being set and resolvconf is using the default values of 8.8.8.8 and 8.8.4.4. The google DNS will not work behind my proxy, I must use the local DNS server. If I edit /etc/resolv.conf and manually enter the local DNS and domain then it works until restart. I know I could do this and then make the file read only, but I these devices also need to work in other locations and I can't hard-code a DNS into each device.