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Nameserver Queries

The resolver sends a question to a name server, of the form: 
{query domain name, type, class}
The server responds with one or more appropriate RRs. It also sends an ADDITIONAL INFORMATION section, which contains extra RRs which the resolver will probably find useful. For example, if a resolver queries for a particular NS RR, the server will return it, plus additional information giving the IP address of the name server specified in the main body of the reply.
 
The most common DNS query is of type A, where the resolver is required to map a domain name to an IP address - that is, "looking up" an IP address. Some typical type A RRs look like: 
ironbark  86400  IN  A  149.144.21.60
redgum    86400  IN  A  149.144.21.3
bindi     86400  IN  A  149.144.20.82
Note that the "domain name" part of these RRs has been omitted (leaving only the hostnames) for clarity.
 

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