6.2.8. QNAME=USC-ISIC.ARPA, QTYPE=CNAME

Connected: An Internet Encyclopedia
6.2.8. QNAME=USC-ISIC.ARPA, QTYPE=CNAME

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6.2.8. QNAME=USC-ISIC.ARPA, QTYPE=CNAME

If this query is sent to either A.ISI.EDU or C.ISI.EDU, the reply would be:

               +---------------------------------------------------+
    Header     | OPCODE=SQUERY, RESPONSE, AA                       |
               +---------------------------------------------------+
    Question   | QNAME=USC-ISIC.ARPA., QCLASS=IN, QTYPE=A          |
               +---------------------------------------------------+
    Answer     | USC-ISIC.ARPA. 86400 IN CNAME      C.ISI.EDU.     |
               +---------------------------------------------------+
    Authority  | <empty>                                           |
               +---------------------------------------------------+
    Additional | <empty>                                           |
               +---------------------------------------------------+

Because QTYPE=CNAME, the CNAME RR itself answers the query, and the name server doesn't attempt to look up anything for C.ISI.EDU. (Except possibly for the additional section.)

Next: 6.3. Example resolution

Connected: An Internet Encyclopedia
6.2.8. QNAME=USC-ISIC.ARPA, QTYPE=CNAME