Charles Steinkuehler's LEAF/LRP Website




     dnsquery [-n nameserver] [-t type] [-c class] [-r retry] [-p period] [-d]
              [-s] [-v] host


     The dnsquery program is a general interface to nameservers via BIND re­
     solver library calls.  The program supports queries to the nameserver
     with an opcode of QUERY.  This program is intended to be a replacement or
     supplement to programs like nstest, nsquery and nslookup.  All arguments
     except for host and nameserver are treated without case-sensitivity.


     -n nameserver
                 The nameserver to be used in the query.  Nameservers can ap­
                 pear as either Internet addresses of the form w.x.y.z or can
                 appear as domain names.  (Default: as specified in

     -t type     The type of resource record of interest.  Types include:
                       A        address
                       NS       nameserver
                       CNAME    canonical name
                       PTR      domain name pointer
                       SOA      start of authority
                       WKS      well-known service
                       HINFO    host information
                       MINFO    mailbox information
                       MX       mail exchange
                       RP       responsible person
                       MG       mail group member
                                DCE or AFS server
                       ANY      wildcard

                 Note that any case may be used.  (Default: ANY.)

     -c class    The class of resource records of interest.  Classes include:
                       IN       Internet
                       HS       Hesiod
                       CHAOS    Chaos
                       ANY      wildcard

                 Note that any case may be used.  (Default: IN.)

     -r retry    The number of times to retry if the nameserver is not re­
                 sponding.  (Default:  4.)

     -p period   Period to wait before timing out.  (Default: RES_TIMEOUT.)

     -d          Turn on debugging.  This sets the RES_DEBUG bit of the re­
                 solver's options field.  (Default:  no debugging.)

     -s          Use a stream rather than a packet.  This uses a TCP stream
                 connection with the nameserver rather than a UDP datagram.
                         list of usable RR types and classes
                         list of resolver flags


     If the resolver fails to answer the query and debugging has not been
     turned on, dnsquery will simply print a message like:
           Query failed (rc = 1): Unknown host

     The value of the return code is supplied by h_errno .


     nslookup(8),  nstest(1),  nsquery(1),  named(8),  resolver(5).


     Bryan Beecher


     Queries of a class other than IN can have interesting results since ordi­
     narily a nameserver only has a list of root nameservers for class IN re­
     source records.

     Dnsquery uses a call to inet_addr() to determine if the argument for the
     ``-n'' option is a valid Internet address.  Unfortunately, inet_addr()
     seems to cause a segmentation fault with some (bad) IP addresses (e.g.,

4th Berkeley Distribution       March 10, 1990                               2

Man(1) output converted with man2html