Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 
New Member

CUCM 10 / Presence 10 - DNS Client


We have historically always disabled DNS client in CUCM as we used it from version 4 up to current version 10. Now I have installed Presence server adn disable DNS client also. But I have realized, how it can communicate with external companies in trust if DNS client is turned off?

I would like to enable DNS client for CUCM and Presence... Is only way to enable it, backup CUCM Published+Subcriber and Presence, reinstall cisco unified OS and enable DNS client in setup, then restore all systems from backup?


Hall of Fame Super Silver

Re: CUCM 10 / Presence 10 - DNS Client

You can easily enable it from CLI.


Sent from Cisco Technical Support iPhone App

New Member

CUCM 10 / Presence 10 - DNS Client

But for example in Finesse I had to reinstall whole machine to fully enable DNS Client. If I just did it in CLI, it didn't work.

VIP Super Bronze

CUCM 10 / Presence 10 - DNS Client

You must have hit a bug or something unique to that product. Enabling DNS isn't a big deal on most products as long as you have the records for the cluster nodes correct. You need both an A and a single PTR record (be careful to delete any duplicates) that correctly resolve the server's FQDN. Screw that bit up and you'll likely experience database replication issues; otherwise, you should be fine.

PS- If you're going to do federation, don't forget to think about what domain the IM&P cluster is in. You'll want it to be your public DNS namespace and not a fictional internal namespace. Example: instead of cisco.local. This is because XMPP typically uses TLS and the handshake will fail if the FQDN contacted from the outside doesn't match the details of the certificate.

Please remember to rate helpful responses and identify helpful or correct answers.

CreatePlease to create content