DDNS with host declarations

Simon Hobson dhcp1 at thehobsons.co.uk
Sun Oct 29 07:21:37 UTC 2006

Jan Engelhardt wrote:

>when dhcpd.conf contains a host declaration, such as
>   host foobar {
>       fixed-address;
>       hardware ethernet 00:aa:bb:cc:dd:ee;
>   }
>then no DDNS update takes place at all. How can I achieve that
>   (a) DDNS updates are made, according to a fixed hostname (set in
>   dhcpd.conf)

'man dhcpd.conf' - look for update-static-leases

>   (b) DDNS updates are made, according to the preferred hostname
>   a client sent (in case it sent one)

I would think "ddns-hostname = <something>" where <something> is an 
expression to get the client supplied hostname. However, since 
clients might not supply a hostname, you probably also need to use a 
pick-first-value to use the client supplied hostname if there is one, 
or the statically defined one if it doesn't.

Be aware that in either case, the dhcp server will do a DNS update 
for every lease renewal (because it doesn't have a lease structure to 
track it with), and it will not delete the record when the lease 

My personal preference is to manually configure the dns when 
configuring static host declarations - or it's something you could 
script using nsupdate (or similar) if you are machine generating your 

More information about the dhcp-users mailing list