I'm having an odd issue with nslookup on my Windows Server setup. When I run a query with a fully qualified domain name (FQDN), like "nslookup hostname.FQDN", I see two timeouts before it finally returns a successful lookup. However, if I just query the hostname with "nslookup hostname", that works fine and there are no timeouts. Also, a direct "A" record lookup with the FQDN returns results immediately. I'm concerned because these timeouts seem to be slowing down access to my web consoles when using FQDNs. My DC/DNS servers are set up with IPv6, and I've tried to configure the servers to only use the IPv4 address or completely disable IPv6 on both the servers and clients, but nothing changes. Does anyone have insights on how to resolve these timeouts?
2 Answers
In my experience with IPv6, we haven’t faced similar issues. Since you've mentioned it's fine with A records and hostnames, but problems arise with FQDN, that’s telling. Are you getting timeouts with AAAA record queries as well? Also, is your Windows Server DNS configured as the authoritative server for that zone or is it set to forward unanswered queries?
It might be related to how the query format is set up rather than a DNS issue. When you run a query with just the hostname, it automatically adds your primary DNS suffix, so it's effectively searching for something like "hostname.ad.contoso.com." instead of just the FQDN. I suggest trying the lookup with a trailing period, like "nslookup hostname.FQDN."
That’s interesting! When I added the trailing dot to my FQDN, it worked without any timeouts. I'm curious why it behaves differently on various networks though, where I can run FQDN without the dot and still not encounter issues.
No forwarding is happening; my server is handling all queries directly.