HP-UX Reference (11i v2 03/08) - 1 User Commands N-Z (vol 2)

n
nsupdate(1) nsupdate(1)
NAME
nsupdate - Dynamic DNS update utility
SYNOPSIS
nsupdate [-d][-v][
-y keyname:secret | -k
keyfile]
DESCRIPTION
nsupdate is used to submit Dynamic DNS Update requests as defined in RFC2136 to a name server.
This allows resource records to be added or removed from a zone without manually editing the zone file.
A single update request can contain requests to add or remove more than one resource record.
Zones that are under dynamic control via
nsupdate or a DHCP server should not be edited by hand.
Manual edits could conflict with dynamic updates and cause data to be lost.
The resource records that are dynamically added or removed with
nsupdate have to be in the same
zone. Requests are sent to the zone’s master server. This is identified by the MNAME field of the zone’s
SOA record.
Options
-d This option makes nsupdate operate in debug mode. This provides tracing information
about the update requests that are made and the replies received from the name server.
Transaction signatures can be used to authenticate the Dynamic DNS updates. These
use the TSIG resource record type described in RFC2845. The signatures rely on a
shared secret that should only be known to
nsupdate and the name server. Currently,
the only supported encryption algorithm for TSIG is HMAC-MD5, which is defined in
RFC 2104.
Once other algorithms are defined for TSIG, applications will need to ensure they select
the appropriate algorithm as well as the key when authenticating each other. For
instance, suitable
key{} and server{} statements would be added to
/etc/named.conf so that the name server can associate the appropriate secret key
and algorithm with the IP address of the client application that will be using TSIG
authentication. nsupdate does not read
/etc/named.conf.
-k This option is used to provide the shared secret needed to generate a TSIG record for
authenticating Dynamic DNS update requests. With this option,
nsupdate reads the
shared secret from the file keyfile, whose name is of the form
Kname.+157.+random.private. For historical reasons, the file
Kname.+157.+random.key must also be present. This option is mutually exclusive
with the -y option.
-v This option makes nsupdate use a TCP connection to send update requests to the name
server. By default, nsupdate uses UDP to send update requests. This may be prefer-
able when a batch of update requests is made.
-y This option is used to generate a signature from keyname:secret. keyname is the name of
the key, and secret is the base64 encoded shared secret. Use of the -y option is
discouraged because the shared secret is supplied as a command line argument in clear
text. This may be visible in the output from ps(1) or in a history file maintained by the
user’s shell.
Input Format
nsupdate reads commands from its standard input. Each command is supplied on exactly one line of
input. Some commands are for administrative purposes. The others are either update instructions or
prerequisite checks on the contents of the zone. These checks set conditions that some name or set of
resource records (RRset) either exists or is absent from the zone. These conditions must be met if the
entire update request is to succeed. Updates will be rejected if the tests for the prerequisite conditions
fail.
Every update request consists of zero or more prerequisites and zero or more updates. This allows a suit-
ably authenticated update request to proceed if some specified resource records are present or missing
from the zone. A blank input line causes the accumulated commands to be sent as one Dynamic DNS
update request to the name server.
The command formats and their meaning are as follows:
Section 1646 Hewlett-Packard Company 1 HP-UX 11i Version 2: August 2003