Question on DHCP lease expiration

[David Li]

Hi,

This is my first post here.

I am testing to see if an expired DHCP lease can result in the removal
of the corresponding DNS record on Centos 7.

So far I am able to let DHCP server assign an static IP based on the
host's MAC address and add a DNS A record. The host is also able to
refresh its lease every time it expires.

But when I shut down the host, I don't see the record removed after
the lease expired (5 min). Even more the syslog doesn't show any
messages from DHCP server attempting to remove the IP address and
update the BIND 9 (named) server. So I am thinking there might be
something wrong or missing in my dhcpd.conf.

Here is a snippet of my dhcpd.conf:


# DNS options

ddns-updates on;
ddns-update-style interim;
update-static-leases on;
authoritative;

allow unknown-clients;
use-host-decl-names on;
default-lease-time 300; #5 min
max-lease-time 300; #5min
log-facility local7;



# static assignment
#
host node1 {
   hardware ethernet 08:00:27:0A:C3:1C;
   fixed-address 10.4.1.11;
   ddns-hostname "node1";
}


Can anyone help to see what's missing from my configuration?

Thanks.