ISC_DHCPd_and_Dynamic_DNS_update

ISC_DHCPd_and_Dynamic_DNS_update#

Making FreeIPA based DNS work with DDNS and dhcpd server requires a couple of steps

A typical dhcpd.conf with working DDNS - without FreeIPA will have a section looking something like the following

# this file includes definition of DDNS_UPDATE key
include "/etc/dhcp/ddns.key";

# replace xxxxxxx as appropriate
zone xxxxxxx.com. {
  primary 127.0.0.1;
  key DDNS_UPDATE;
}

# replace 2.0.10 with your reverse ip
zone 2.0.10.in-addr.arpa. {
  primary 127.0.0.1;
  key DDNS_UPDATE;
}

The corresponding part of named.conf will look like this (not complete file, this is after the options section):

# note that this file is identical to /etc/dhcp/ddns.key
# not experimented with pointing to same file which
# could be tricky if you are chroot
include "/var/named/named.keys";

zone "xxxxxxx.com" {
    type master;
    file "masters/db.xxxxxxx.com";
    allow-update { key DDNS_UPDATE; };
};

zone "2.0.10.in-addr.arpa" {
    type master;
    file "masters/rev.2.0.10";
    allow-update { key DDNS_UPDATE; };
};

Assuming you started with a working DDNS setup your files will look something similar. Once you install FreeIPA this will no longer work. This is because the database is now moved to inside the LDAP server. The zone section is now deleted and moved into LDAP.

You can update your zone definition inside FreeIPA and add

grant DDNS_UPDATE wildcard * ANY;

to the zone definition.

Category:How to