Dynamic Update ISC DHCP Stale Records

[Chris Cox]

briandesu wrote:
> Ladies & Gents,
> 
> I have set up a BIND 9.2.1 server and ISC DHCP 3.0 server to perform
> dynamic updates for Active Directory.  However, I am having a problem
> with stale records.
> 
> Is it possible to configure the ISC DHCP server to remove the stale
> records in the same fashion that a M$ dhcp server removes stale A and
> PTR records from a Winbloze dns server?  If yes, what are the required
> parameters in the dhcpd.conf file?

What's the problem with an A record??  If something else needs
to consume the address/name, ISC dhcp will do the right thing and
clean out the old A/PTR records (unlike M$).  What's the harm
in keeping the entry??  Even if the lease expires, the client
will likely request the last address it had.. so unless you
have a fully loaded dhcp pool... your client hosts will just get
back the same address anyway.

I've never had a problem with the extra entries.  If it really
bugs you (and I would hope that it wouldn't), you could write
a quick script to determine expired dhcp entries and fire off
dynamic update requests using nsupdate from the dhcp server
to remove the "stale" entries.... but I personally think it's
not necessary to do this (this method could be very accident
prone).