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DNSQUERY

Section: User Commands (1)
Index
BSD mandoc
BSD 4 

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

Thednsqueryprogram is a general interface to nameservers viaBIND resolver library calls. The program supportsqueries to the nameserver with an opcode of QUERY.This program is intended to be a replacement orsupplement to programs like nstest, nsquery andnslookup. All arguments except forhostandnameserverare 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:

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 isnot 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'sFt optionsfield. (Default: no debugging.)

-s

Use astreamrather than a packet. This uses a TCP stream connection withthe nameserver rather than a UDP datagram. This sets theRES_USEVC bit of the resolver'sFt optionsfield. (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 search lists

<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 beenturned on,dnsquerywill simply print a message like:

Query failed (rc = 1) : Unknown host

The value of the return code is supplied by Ft 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 resultssince ordinarily a nameserver only has a list of root nameserversfor class IN resource records.

Dnsquery uses a call to Fn inet_addr to determine if the argumentfor the ``-n''option is a valid Internet address. Unfortunately,Fn inet_addr seems to cause a segmentation fault with some (bad)IP addresses (e.g., 1.2.3.4.5).

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Index

NAME

SYNOPSIS

DESCRIPTION

OPTIONS

FILES

DIAGNOSTICS

SEE ALSO

AUTHOR

BUGS

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