IPv6 DDNS with dhcp-4.2.1

Jonathan Barber jonathan.barber at gmail.com
Wed Mar 16 17:56:02 UTC 2011


I'm trying (and failing) to get dhcpd to update my DNS server with the
hostname defined by the name of the host declarations for IPv6
clients.

I'm using the 4.2.1 release of the ISC DHCP as the DHCP server,
compiled on Red Hat 5.4 x86_64. My test client is the stock "dhcp6c"
programs on RHEL5.4 x86_64.

My dhpcd configuration is as follows:
ddns-update-style  interim;
option dhcp6.name-servers  fe80:0:0:0:250:56ff:fe99:123;
option domain-name         bork;

key dhcpupdate {
  algorithm  hmac-md5;
  secret     KEOh21UeVROIuQFECY8hNA==;
}

zone bork. {
  primary    10.112.29.250;
  key        dhcpupdate;
}

host ies-dev-gluster3 {
	log(error, concat("IPV6: ", host-decl-name));
	fixed-address6 fc00::2;
	host-identifier option dhcp6.client-id
00:01:00:01:15:12:53:b9:48:5a:8a:2f:e0:2a;
	ddns-hostname = host-decl-name;
}

subnet6 fc00::/7 {
}

I start the server with:
dhcpd -6 -cf /etc/dhcpdv6.conf -lf /var/lib/dhcpv6/server6.leases

Running the client I get the new IPv6 address, and it updates the
nameserver configuration in /etc/resolv.conf - but the dhcpd doesn't
update the DNS - in fact it looks like the daemon doesn't even try to
contact the DNS server.

I see the following messages in the log:
Mar 16 17:17:27 ns0 dhcpd: Solicit message from
fe80::250:56ff:fe99:138 port 546, transaction ID 0xEB300B00
Mar 16 17:17:27 ns0 dhcpd: data: host_decl_name: not available
Mar 16 17:17:27 ns0 dhcpd: data: host_decl_name: not available
Mar 16 17:17:27 ns0 dhcpd: Sending Advertise to fe80::250:56ff:fe99:138 port 546
Mar 16 17:17:28 ns0 dhcpd: Request message from
fe80::250:56ff:fe99:138 port 546, transaction ID 0x7D2D5400
Mar 16 17:17:28 ns0 dhcpd: data: host_decl_name: not available
Mar 16 17:17:28 ns0 dhcpd: data: host_decl_name: not available
Mar 16 17:17:28 ns0 dhcpd: Sending Reply to fe80::250:56ff:fe99:138 port 546

I've tried setting the "ddns-hostname" parameter to a constant value
and nothing happens. Ditto if I remove the parameter completely.

I've used almost exactly the same configuration of IPv4, and it works,
so I don't think I'm doing anything stupid.

Should it work? Can anyone see if I'm missing something obvious?

Cheers
-- 
Jonathan Barber <jonathan.barber at gmail.com>



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