I have a number of servers on our local network and our debian server has suddenly stopped being able to access the other servers via their FQDN. Initial symptom was inability to login with Active Directory accounts. On further inspection, this machine, porkbelly, was unable to access our other servers (e.g. bacon and albert) via their FQDN. That is, they can ping albert by running ping albert but not by running ping albert.domain.local though when running ping albert it will be expanded to albert.domain.local. The server is still accessible from other servers via both porkbelly and porkbelly.domain.local. Upon examination of hosts information and running hostname its hostname and FQDN are correct. The resolv.conf appears correct. It contains: domain domain.local search domain.local nameserver 192.168.0.xxx (the nameserver) The dns server is also our Windows AD server. I'm not even sure where to go from here or why dns seems to be partially working though I don't have much experience. Where should I go from here? What might be causing this issue where machines are visible via their hostname but not their FQDN?