I have my DHCP server feeding into /etc/hosts. I have my DNS server forwarding dns, and also serving the contents of /etc/hosts.
The DNS server only gives out addresses that were in /etc/hosts when the dns forwarder was started, but doesn't pick up new ones.
Plug in wap-3c34. It shows in DHCP leases:
10.35.2.8 78:8a:20:0a:0e:c8 2018/05/24 14:58:59 wap-3c34
But isn't available in DNS:
$ host wap-3c34 Host wap-3c34 not found: 3(NXDOMAIN)
If we do run restart dns forwarder on our firewall:
$ host wap-3c34 wap-3c34.admin.codethink.co.uk has address 10.35.2.8
Talking to @dmbaturin in IRC:
<dmbaturin> thinkl33t: Ok, now this is tricky. Since DHCPD doesn't execute anything when it gives a new lease (AFAIR), we'd have to teach pdns to re-read the hosts file for that.