fixed-address6 and ddns-hostname

Simon Hobson dhcp1 at
Tue Sep 23 10:29:16 UTC 2014

winsor at wrote:

> But if I add a configuration for fixed host:
> subnet6 2001:db8::/48 {
> 	pool6 {
>                range6 2001:db8:3::/64;
>                allow members of "winsor_intf";
> 		  host wpad {
>                        host-identifier option dhcp6.client-id 00:01:00:01:1a:16:60:1e:b4:b5:2f:90:df:13;
>                        ddns-hostname "wpad"; #or without ddns-hostname - ddns does not work
>                        fixed-address6 2001:db8:3:0::100;
>                }
>        }
> }
> dhcpd not send ddns query to bind.

No it won't. Assuming it behaves the same in IPv6 mode as in IPv4 mode, then fixed addresses assigned via a host statement do **NOT** result in the normal lease lifecycle processing - no lease record, no DDNS updates, etc.
Again assuming things work the same, you could create a skeleton lease for the client (or adapt one that the system has created) and add the "reserved" keyword to it. The address (although dynamic) will then be reserved of that client even after expiration.

Also, do **NOT** put host statements in any scope but global (or a group that's in the global scope). Regardless of where they are defined, they are considered global so can match a client even if it's in a totally unrelated scope (eg another subnet). But, it will still inherit properties from where it is defined which is very highly unlikely to be correct - eg wrong gateway was an example we had on this list a while back in the IPv4 space !

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