One the topics that is generally overlooked is the creation of a solid DNS architecture. These days DNS is relied upon to maintain the upkeep of any domain, in my opinion Cisco UC products are much more aligned to using DNS than the old ways of just plugging in an IP Address for each service. The project I undertake now, I’ll always ensure the DNS architecture is looked at and configured first. It’s amazing how smooth a Cisco UC implementation is with the DNS infrastructure configured according to best practices.

In this article, I will touch on DNS and records that are created to ensure a smooth initial implementation.

The Cisco Install will throw an error during install if you enable DNS Client and have not yet created the DNS A Records! I like to plan and document all the DNS Records I’ll need for the Cisco UC install in its entirety. But obviously this is not a necessity.

For all you Cisco geeks out there, we are going to spend most of time with modifying the Forward Lookup zone. This is the zone by which DNS Names are resolved to IP Addresses and just for completeness the Reverse Zone is for resolving IP Addresses to DNS Names.

Right-Click on the Forward-Lookup zone and select New Host (A or AAAA) Record.

Enter the Name of your CUCM Publisher, as you enter the name, the ‘Fully qualified domain name (fqdn) is auto populated.

Now enter the IP Address of the CUCM Publisher. Be sure to check the box “Create associated pointer (PTR) record”. This is the record that will sit in the Reverse Lookup zone.

Repeat this process for every Cisco UC server. CUCM publisher, subscribers, CUC Publisher and subscribers, IMP/CUPs publisher and subscribers, Cisco VCSc and VCSe servers etc, you get my drift.

At this point you can go ahead and install your servers without errors.