A Linux administrator is investigating an issue with an internal Linux server that is unable to resolve the following internal addresses: The administrator runs the following commands as part of troub

When a server is configured with the correct internal DNS server in resolv.conf but still cannot resolve internal names, the most common cause is a firewall blocking outbound UDP/TCP traffic on port 53. Allowing outbound DNS traffic from the server to the internal DNS server's IP on port 53 enables the queries to reach the resolver without requiring changes to the DNS server's records or the client's resolver configuration.

Publishing internal hostnames like fileshare.example.internal in public DNS exposes internal network topology, is a security risk, and would not be accessible from inside the network without proper internal resolution anyway.

Installing a local caching DNS server does not resolve the underlying network connectivity issue that is preventing DNS queries from reaching the existing internal DNS server.

If resolv.conf already points to the internal DNS server, changing it again will not help - the problem is that firewall rules are dropping the DNS packets before they reach the server.