/etc/resolv.conf
to get the default ns and search lists
dnsquery1
Query domain name servers using resolver
Usage
dnsquery [-n
nameserver]
[-t
type]
[-c
class]
[-r
retry]
[-p
period]
[-d]
[-s]
[-v]
host
Overview
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:
- 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 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
-
-
<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.