DHCPv6 and DDNS

[Philippe Clérié <philippe@gcal.net>]

Hello,

For the past couple of days I've been trying to set up isc-dhcp-server 
on jessie for IPv6. I am at a point where the server is providing 
addresses but I cannot get it to update the DNS server.

Both servers are on the same machine. The DNS server is bind9 and is 
working correctly for both IPv4 and IPv6. DHCPv4 is updating DNS with no 
problems and I can manage IPv6 addresses using nsupdate.

The last change I attempted in my dhcpd6.conf was to set 
ddns-update-style to "standard" instead of "interim" as suggested by ISC 
(https://deepthought.isc.org/article/AA-01091/0/ISC-DHCP-support-for-Standard-DDNS.html). 
Setting update-optimization to false is also recommended.

Note that interim style does not work either. In fact, the only time I 
saw some traffic from the DHCP transaction was just after changing to 
standard style. There was a bunch of denied DNS queries from the 
link-local address of the DHCP client. I allowed queries from fe80::/10 
to the DNS servers and thoses messages disappeared.

I have also tried removing any existing lease on the client side before 
attempting the connection. The only difference is that I get the 
4-messages exchange with the DHCP server instead of the 2-message exchange.

Static leases on DHCPv4 are updated provided update-static-leases is on, 
so I presume the behavior is the same with v6.

======== dhcpd6.conf =======
log-facility local7;

ddns-updates on;
ddns-update-style standard;
update-optimization false;

update-static-leases on;
update-conflict-detection false;

zone example.com {
        primary altair.example.com;
}

zone x.x.x.x.x.x.x.x.x.x.x.x.1.0.0.2.ip6.arpa {
        primary altair.example.com;
}

shared-network VLAN0_POOL_IP6 {
	authoritative
	option dhcp6.name-servers 2001:xxx:xxxx:xxxx::16;
	option dhcp6.domain-search "example.com";
	default-lease-time 28800;
	max-lease-time 86400;
	min-lease-time 7200;
	ddns-domainname "example.com.";
	ddns-rev-domainname "ip6.arpa.";

	host alcor {
		# IPv4 172.28.5.12
	        fixed-address6 2001:xxxx:xxxx:xxxx::12;
        	hardware ethernet 80:1f:02:bf:05:0e;
	        default-lease-time 259200;
	        max-lease-time 604800;
	        min-lease-time 86400;
	}

        subnet6 2001:xxxx:xxxx:xxxx::/64 {
                range6 2001:xxxx:xxxx:xxxx::1:101
			2001:xxxx:xxxx:xxxx::1:130;
        }
}

===============================

So in this fragment, server alcor gets both IP addresses correctly but 
only the IPv4 address is entered in DNS.

I have not gotten around to testing allocation from the reserved range. 
I am much more concerned with the static reservations.

So far I have not seen any trace of an attempt by the DHCPv6 server to 
update the DNS.

Thanks in advance for any suggestion...

--
Philippe

------
The trouble with common sense it that it is so uncommon.
<Anonymous>