Why is nslookup reporting two IP addresses

domain-name-systemnslookup

I made a DNS change a few hours ago and I just ran the following command with the following output:

nslookup mydomain.com ns1.mynameserver.com
Server:  ns1.mynameserver.com
Address:  111.111.111.111

Name:    mydomain.com
Addresses:  222.222.222.222
      333.333.333.333

222.222.222.222 is old IP. 333.333.333.333 is the new IP address. Why are they both showing up? Since I'm querying the authoritative DNS server directly, shouldn't only the new IP address be shown?

Best Answer

Neglecting to remove the old address is exactly what happened. It's not something that would occur when the old record is still in cache when the new one is added or something like that - a different new answer always fully replaced an old answer for a RR in a cache.

There's a record for the old address somewhere in the zone file, and a record for the new address somewhere in there, too. There are several valid syntax methods by which the record can be defined in the zone - it could be easy to overlook if they weren't specifically looking for the record to remove.

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