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DNSQUERY(1) BSD General Commands Manual DNSQUERY(1)

NAME

dnsquery ? query domain name servers using resolver

SYNOPSIS

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

DESCRIPTION

The dnsquery program is a general interface to nameservers via BIND resolver 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.

OPTIONS

       ?n nameserver

The nameserver to be used in the query. Nameservers can appear as either Internet addresses of the form w.x.y.z or can appear as domain names. (Default: as specified in /etc/resolv.conf.)

?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
AFSDB

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:

’ 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 responding. (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 resolver’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. This sets the RES_USEVC bit of the resolver’s options field. (Default: UDP datagram.)

?v’ Synonym for the ‘‘?s’’ flag.

host’ The name of the host (or domain) of interest.

FILES

      /etc/resolv.conf’                    to get the default ns and searchlists

<arpa/nameser.h>
list of usable RR types and classes
<resolv.h>
list of resolver flags

DIAGNOSTICS

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.

SEE ALSO

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

AUTHOR

Bryan Beecher

BUGS

Queries of a class other than IN can have interesting results since ordinarily a nameserver only has a list of root nameservers for class IN resource 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., 1.2.3.4.5).

4th Berkeley Distribution March 10, 1990 4th Berkeley Distribution

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