dynamic dns cleanup?

[Nicolas C.]

On 2015-06-25 21:47, Cuttler, Brian (HEALTH) wrote:
> This is a dhcpd/dynamic dns interaction question, but the question is
> I think really a dhcpd question.
> 
> I have a printer that was in "this" building, which uses dynamic dhcp
> to register DNS entries, this worked as expected, address assigned,
> Forward and Reverse records created. All good.
> 
> We have now moved the printer to one of our other building, which does
> NOT use dynamic DNS. The printer was assigned a new IP address (in the
> range assigned to that building, according to the helper addresses in
> the network router), that part is all good, worked as expected.
> 
> I was wondering about cleanup of the original DNS entries, the ones in
> the dynamic range in building #1. The entry looks like
> hri12028.esp122.wadsworth.org (printer tag/name, subnet/range, network
> name). Will that at some point go away on its own, or get over
> written?
> 
> Will it be removed when the dhcp entry for that zone expires, or when
> the IP is ultimately reassigned?
> 
> Or will I need to manually remote the DNS entry if I want to have it
> 'go-away'?

When the DHCP assigns the address, it keeps some info in the 
dhcpd.leases file (host name, IP address, client-id, hardware address, 
content of the forward/reverse/TXT records, etc.). When the lease of the 
client expires, the DHCP use this information to perform the DNS 
cleanup.

So, if everything is correctly configured, the DNS entry will go away 
automatically at the end of the lease.

Nicolas C.