DHCP and DNS infrastructure services are quite good for working
together. So Zentyal whose aim is to provide a tightly integrated
product had to make it work together.

Its cooperation is based on DHCP server asking to add the DHCP clients
in DNS zones. For instance, your client called foo asks for a IP
address lease to connect to your local network. Once the lease is
done, the DHCP server ask to DNS server to add foo client with the
given IP address to the configured dynamic DNS zone, for example,
example.lan.

Therefore, if you ask for foo.example.lan then the leased IP address
is returned, and reverse resolution also returns as expected.

The above explanation was the simplest and easiest to understand by
Zentyal community as these posts reminds me. But I thought the right
way to do it is to set the hostname by the sysadmin. That is, if your
host is a dynamic one and it is not a server, then a dynamic name is
set such as dyn-192.168.0.1.example.lan . Furthermore, due to time
constraints I was not able to finish a complete dynamic DNS + DHCP feature in
the past and reverse resolution was not implemented. That was odd for
Zentyal users although it is stated clearly in the documentation.

So, we decided to fix these things when a slot of time was available, so
I was able to finish the proper implementation with this shiny
features:

  • Set the hostname based on DHCP client data when the client belongs to a DHCP range
  • Reverse resolution is working for DHCP client names
  • Mix static and dynamic defined DNS zones

The latter feature is a very neat one. This allows you as Zentyal
administrator to have a DHCP server assigning names and IP addresses
dynamically, as the hosts requests and releases demands to, and you as
system administrator are able to manage the zone to add different
resource records to that zone, such as, specific host names, alias,
name servers or mail exchangers.

In order to do that, I used nsupdate tool to dynamically set the
manual settings in a dynamic zone allowing us not to corrupt the
journal file by named daemon and be as kind as possible with bind.

List of DNS domains

Dynamic and static DNS domains

To sum up, to maximise this new feature you firstly must create a domain in
DNS section and then select it in the Dynamic DNS options from DHCP
section. Once this is done, save changes. Then, every new client
request will update your DNS zones to give direct and reverse
resolution for this name – IP address pair.

Dynamic DNS options in DHCP module

Dynamic DNS options in DHCP module

This feature is available in 2.X package series of Zentyal server. Namely, ebox-dns 2.0.3 and ebox-dhcp 2.0.4 are the packages with this feature.

Listening to your community requirements usually make your product better! :)

Best regards and thanks a million for your feedback on this great feature!

Edit: I have updated the post to include the definite version of the packages.

A post by Enrique Hernandez