$Id: Dynamic-DNS-DHCP.txt,v 1.1 2008/02/13 22:34:40 jerry Exp $

Dynamic DNS and DHCP
--------------------

using BIND 9 and ISC DHCPD v3 

DNS
---

Create a dnssec key
# dnssec-keygen -a hmac-md5 -b 128 -n USER dhcpupdate

produced 2 files called
Kdhcpupdate.+157+64338.key
Kdhcpupdate.+157+64338.private

The key is the last token in the .key file

update named.conf
key dhcpupdate {
  algorithm hmac-md5;
  secret "YOUR_KEY_GOES_HERE";
};

add  allow-update { key dhcpupdate; };  to zones to be updated

restart named with kill -HUP or
/etc/rc.d/named stop
/etc/rc.d/named start

Test it using nsupdate

# nsupdate
> server marles.internal
> key dhcpupdate YOUR_KEY_GOES_HERE
> zone internal
> update add wibble.internal. 600 IN A 192.168.1.50
> send
> zone 1.168.192.in-addr.arpa
> update add 50.1.168.192.in-addr.arpa 600 IN PTR wibble.internal.
> send

# host wibble.internal
wibble.internal has address 192.168.1.50
# host 192.168.1.50
50.1.168.192.in-addr.arpa domain name pointer wibble.internal.

delete it

# nsupdate
> key dhcpupdate YOUR_KEY_GOES_HERE
> update delete wibble.internal
> send
> update delete 50.1.168.192.in-addr.arpa
> send


DHCP
----

in /usr/local/etc/dhcpd.conf add

ddns-update-style interim;

key dhcpupdate {
  algorithm hmac-md5
  secret YOUR_KEY_GOES_HERE;
}

zone internal {
  primary marles.internal;
  key dhcpupdate;
}

zone 1.168.192.in-addr.arpa {
  primary marles.internal;
  key dhcpupdate;
}

Restart dhcpd and check its working
error will appear in /var/log/messages
leases are in kept in /var/db/dhcpd.leases

/*** end ***/