A lot of times I need to see if a host's reverse DNS matches the A record it's associated with. So, what I do is nslookup superuser.com followed by nslookup 64.34.119.12. Is there a way to get nslookup to do this in one step?
Answer
Unfortunately, the PTR and A records are on different servers. The owner of the domain will have name servers for the A record. Smaller users will have IP addresses provided by a separate organization. That organization will have have their own name servers for the PTR records. Even where both were on the same servers, different queries are required. Even zone transfers would not work as the data is in different zones.
If you are repeating the same lookups, which is common if you are running an MX mail server, consider setting up a caching nameserver on the same host. A program like dnsmasq provides a light-weight caching name server with a limited (but configurable) cache size. However, dnsmasq doesn't run on Windows. Running bind, which is available for Windows, as a caching name server provides full functionality at the expense of a possibly more complicated configuration. In either case, the name server cache should not be accessible from the Internet, but must be able to query the Internet.
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