DNS Updates
Keys
We configured the DNS Servers to allow updates using keys. Those keys need to be available on the system that sends the DNS updates. The keys are already on the DHCP server, so it makes sense to make the DNS updates from the DHCP server.
nsupdate
The utility to make DNS updates is called nsupdate. When running it, it takes two important parameters -v to send updates by TCP rather than UDP and -k to tell it which file the update key is in.
Install
apt-get install dnsutils
Update
nsupdate -k /etc/dhcp/ddns-update.kallenberg.dk -v
You now have a prompt where you can enter the update commands.
Adding a Host
dhcp01
IP-address: 192.168.1.36
update add dhcp01.kallenberg.dk 86400 A 192.168.1.36 send update add 36.1.168.192.in-addr.arpa. 86400 PTR dhcp01.kallenberg.dk. send
Removing a Host
dhcp01
IP-address: 192.168.1.36
update delete dhcp01.kallenberg.dk IN A 192.168.1.36 send update delete 36.1.168.192.in-addr.arpa. PTR dhcp01.kallenberg.dk. send