new

    $update = new Net::DNS::Update;
    $update = new Net::DNS::Update( 'example.com' );
    $update = new Net::DNS::Update( 'example.com', 'HS' );

Returns a Net::DNS::Update object suitable for performing a DNS dynamic update. Specifically, it creates a packet with the header opcode set to UPDATE and the zone record type to SOA (per RFC 2136, Section 2.3).

Programs must use the push() method to add RRs to the prerequisite, update, and additional sections before performing the update.

Arguments are the zone name and the class. If the zone is omitted, the default domain will be taken from the resolver configuration. If the class is omitted, it defaults to IN.

Add a new host

    #!/usr/bin/perl
    use Net::DNS;
    # Create the update packet.
    my $update = new Net::DNS::Update('example.com');
    # Prerequisite is that no A records exist for the name.
    $update->push( pre => nxrrset('foo.example.com. A') );
    # Add two A records for the name.
    $update->push( update => rr_add('foo.example.com. 86400 A 192.168.1.2') );
    $update->push( update => rr_add('foo.example.com. 86400 A 172.16.3.4') );
    # Send the update to the zone's primary master.
    my $resolver = new Net::DNS::Resolver;
    $resolver->nameservers('primary-master.example.com');
    my $reply = $resolver->send($update);
    # Did it work?
    if ($reply) {
            if ( $reply->header->rcode eq 'NOERROR' ) {
                    print "Update succeeded\n";
            } else {
                    print 'Update failed: ', $reply->header->rcode, "\n";
            }
    } else {
            print 'Update failed: ', $resolver->errorstring, "\n";
    }

Add an MX record for a name that already exists

    my $update = new Net::DNS::Update('example.com');
    $update->push( prereq => yxdomain('example.com') );
    $update->push( update => rr_add('example.com MX 10 mailhost.example.com') );

Add a TXT record for a name that doesn't exist

    my $update = new Net::DNS::Update('example.com');
    $update->push( prereq => nxdomain('info.example.com') );
    $update->push( update => rr_add('info.example.com TXT "yabba dabba doo"') );

Delete all A records for a name

    my $update = new Net::DNS::Update('example.com');
    $update->push( prereq => yxrrset('foo.example.com A') );
    $update->push( update => rr_del('foo.example.com A') );

Delete all RRs for a name

    my $update = new Net::DNS::Update('example.com');
    $update->push( prereq => yxdomain('byebye.example.com') );
    $update->push( update => rr_del('byebye.example.com') );

Perform a DNS update signed using a BIND key file

    my $update = new Net::DNS::Update('example.com');
    $update->push( update => rr_add('foo.example.com A 10.1.2.3') );
    $update->push( update => rr_add('bar.example.com A 10.4.5.6') );
    $update->sign_tsig( "$dir/Khmac-sha512.example.com.+165+01018.private" );

The corresponding public key file may also be used:

    $update->sign_tsig( "$dir/Khmac-sha512.example.com.+165+01018.key" );

Another way to perform a signed update

    my $key_name = 'tsig-key';
    my $key      = 'awwLOtRfpGE+rRKF2+DEiw==';
    my $update = new Net::DNS::Update('example.com');
    $update->push( update => rr_add('foo.example.com A 10.1.2.3') );
    $update->push( update => rr_add('bar.example.com A 10.4.5.6') );
    $update->sign_tsig( $key_name, $key );

Perform a signed update with a customized TSIG record

    my $key_name = 'tsig-key';
    my $key      = 'awwLOtRfpGE+rRKF2+DEiw==';
    my $tsig = new Net::DNS::RR("$key_name TSIG $key");
    $tsig->fudge(60);
    my $update = new Net::DNS::Update('example.com');
    $update->push( update     => rr_add('foo.example.com A 10.1.2.3') );
    $update->push( update     => rr_add('bar.example.com A 10.4.5.6') );
    $update->push( additional => $tsig );