NSUPDATE (8)
nsupdate
update Internet name servers interactively
SYNOPSIS
nsupdate
Fl Ar k keydir:keyname
Fl Ar d
Fl Ar v
Ar filename
DESCRIPTION
Nsupdate
is a program to update Internet domain name servers
supporting dynamic update.
Nsupdate
uses the DNS resolver library to pass messages
to a DNS server requesting the additional or deletion of
DNS resource records (RRs).
Nsupdate
reads input from
filename
or standard input.
ARGUMENTS
-tag -width Fl
Fl k
Sign updates with TSIG.
Fl d
Debug mode.
Fl v
Virtual circuit - use TCP to communication with server.
Default is UDP.
INPUT FORMAT
Nsupdate
reads input records, one per line,
each line contributing a resource record to an
update request.
All domain names used in a single update request
must belong to the same DNS zone.
A blank line causes the accumulated
records to be formated into a single update request
and transmitted to the zone's authoritative name servers.
Additional records may follow,
which are formed into additional,
completely independent update requests.
For the last request to be transmitted, a blank line
must end the input.
Records take one of two general forms.
Prerequisite
records specify conditions that must be satisfied before
the request will be processed.
Update
records specify changes to be made to the DNS database.
A update request consists of zero or more prerequisites
and one or more updates.
Each update request is processed atomically -
all prerequisites must be satisfied, then all updates
will be performed.
Nsupdate
understands the following input record formats:
-ohang
prereq nxdomain Va domain-name
Requires that no RR of any type exists with name
domain-name .
prereq yxdomain Va domain-name
Requires that at least one RR named
domain-name
must exist.
Xo
prereq nxrrset Va domain-name Op class
type
Requires that no RR exists of the specified
type
and
domain-name .
Xo
prereq yxrrset
domain-name Op class
type Op data...
Requires that a RR exists of the specified
type
and
domain-name .
If
data
is specified, it must match exactly.
Xo
update delete
domain-name Op class
Op type Op data...
Deletes RRs named
domain-name .
If
type
(and possibly
data )
is specified,
only matching records will be deleted.
Xo
update add
domain-name ttl Op class
type data...
Adds a new RR with specified
ttl , type ,
and
data .
EXAMPLES
The following example illustrates the interactive use of
nsupdate
to change an IP address by deleting any existing A records
for a domain name and then inserting a new one.
Since no prerequisites are specified,
the new record will be added even if
there were no existing records to delete.
Note the
trailing blank line, required to process the request.
-literal -offset indent
$ nsupdate
> update delete test.example.com A
> update add test.example.com 3600 A 10.1.1.1
>
In this example, a CNAME alias is added to the database
only if there are no existing A or CNAME records for
the domain name.
-literal -offset indent
$ nsupdate
> prereq nxrrset www.example.com A
> prereq nxrrset www.example.com CNAME
> update add www.example.com 3600 CNAME test.example.com
>
In this example, the nsupdate will be signed with the key "mykey", which
is in the directory "/var/named/keys".
-literal -offset indent
$ nsupdate -k /var/named/keys:mykey
> update add ftp.example.com 60 A 192.168.5.1
>
DIAGNOSTICS
-ohang
Qq send error
Typically indicates that the authoritative nameservers could not be reached
Qq failed update packet
Typically indicates that the nameserver has rejected the update,
either because the nameserver doesn't support dynamic update,
or due to an authentication failure
Qq res_mkupdate: packet size = Va size
(and no other messages)
The update was successfully received and authenticated by the nameserver.
The prerequisites, however, may have prevented the update from actually
being performed. The only way to determine if the update was performed
is to use debug mode
( d )
and examine the status field in the nameserver's reply.
FILES
SEE ALSO
- named (8) -
- resolver (3) -
- resolver (5) -
; RFC-1034 Domain Names - Concepts and Facilities ; RFC-1035 Domain Names - Implementation and Specification ; RFC-2136 Dynamic Updates in the Domain Name System
AUTHOR
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