Dynamic DNS update utility
nsupdate [-d] [[-y [hmac:]keyname:secret] | [-k keyfile]] [-t timeout] [-u udptimeout] [-r udpretries] [-R randomdev] [-v] [filename]
QNX Neutrino
See http://netbsd.gw.com/cgi-bin/man-cgi?nsupdate++NetBSD-5.0 in the NetBSD documentation.
The nsupdate utility 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. For more information, see http://netbsd.gw.com/cgi-bin/man-cgi?nsupdate++NetBSD-5.0 in the NetBSD documentation.