topic Re: Changing the DNS settings may in Unified Communications Infrastructure

[CUCM] Change DNS server IP

Firdaush Ginowrie — Tue, 19 Mar 2019 18:36:10 GMT

Hello,

How can I change the DNS server IP on the CUCM? Can i change it over the Web Gui ?

Regards,

Fird

you cannot change DNS IP thru

Mohammed Khan — Mon, 19 Sep 2016 08:44:21 GMT

you cannot change DNS IP thru GUI, CLI is the only option

Refer below command

set network dns

This command sets the IP address for the primary or secondary DNS server.

Command syntax

set network dns { primary | secondary } ip-address

http://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/cli_ref/8_6_1/cli_ref_861.html#pgfId-39980

Hi Mohammed,

Firdaush Ginowrie — Mon, 19 Sep 2016 08:59:30 GMT

Hi Mohammed,

Thanks.

What i need to do in case to change the DNS ?

set network dns primary 4.2.2

Mohammed Khan — Mon, 19 Sep 2016 09:06:32 GMT

set network dns primary 4.2.2.2

Command will overwrite the existing DNS Server IP.

Changing the DNS settings may

Gordon Ross — Mon, 19 Sep 2016 10:45:22 GMT

Changing the DNS settings may cause the server to reboot. It will also affect the license MAC that licenses are tied to.

GTG

Do i need to reboot the CUCM

Firdaush Ginowrie — Wed, 21 Sep 2016 09:46:02 GMT

Do i need to reboot the CUCM service?

Reboot is not required,

Mohammed Khan — Wed, 21 Sep 2016 10:12:43 GMT

Reboot is not required,

this command causes a temporary loss of network connectivity. If you change the IP address of the DNS server, you must restart Cisco Tomcat.

Re: Reboot is not required,

Adam Hinchliff — Mon, 06 Aug 2018 11:11:27 GMT

Does this mess around with the license side of things? DNS change should be pretty straight forward right?

Re: Reboot is not required,

Jaime Valencia — Mon, 06 Aug 2018 14:35:13 GMT

Only if you're running 8.x and below it would change the licenses.

Re: Reboot is not required,

Adam Hinchliff — Wed, 12 Sep 2018 05:16:10 GMT

Hi Jamie,

Do you know if we have to restart all services or just tomcat?

We simply want to point our Cucm10x to a new internal DNS server.

Thanks Adam

Re: Changing the DNS settings may

Adam Hinchliff — Tue, 06 Nov 2018 05:18:30 GMT

Im talking about changing the DNS of the interface of call manager. I don't understand how that would be tied into licensing? I would have thought it was just using DNS to resolve other servers in the cluster.

Re: Changing the DNS settings may

Adam Hinchliff — Tue, 06 Nov 2018 05:21:58 GMT

Example:

admin:show network eth0
Ethernet 0

DHCP : disabled Status : up
IP Address : 1xx.xx.1.x IP Mask : 255.255.255.000
Link Detected: yes Mode : Auto disabled, Full, 1000 Mbits/s
Duplicate IP : no

DNS
Primary : 1.1.1.1 Secondary : 2.2.2.2 ( I JUST WANT TO CHANGE THESE)
Options : timeout:5 attempts:2
Domain : adam.com.au
Gateway : 1xx.xx.1.1 on Ethernet 0

Do i only need to restart Tomcat for this?

Cheers

Adam

Re: Changing the DNS settings may

techslusk — Thu, 15 Nov 2018 16:21:00 GMT

Just found a customer that never set it on some subs and was doing research but yes it will interfer with licensing per cisco documentation below. I believe this is only 8.x but not 100%.

Usage Guidelines

If Cisco Unified Communications Manager or Cisco Unity Connection is installed on VMware, the set network dns primary command changes the calculated value of the license MAC and invalidates the Unified CM or Connection license.

For more information about replacement Unified CM licenses, see the section “Obtaining Rehosted Licenses When You Change License MAC Parameters” in the Installing Cisco Unified Communications Manager Release 8.0(2) guide at http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/install/8_0_2/install/cmins802.html#wp524389.

For information about replacement Connection licenses, see the “Managing Licenses in Cisco Unity Connection” chapter of the System Administration Guide for Cisco Unity Connection at http://www.cisco.com/en/US/products/ps6509/prod_maintenance_guides_list.html .

Re: Changing the DNS settings may

Ganeshamoorthy M — Fri, 10 May 2019 15:48:58 GMT

Hi Adam,

do I need to remove and add PLM instance instance and reboot cluster for this DNS IP address change?

I am using CUCM 10.5 version

"DNS
Primary : 1.1.1.1 Secondary : 2.2.2.2 ( I JUST WANT TO CHANGE THESE)
Options : timeout:5 attempts:2
Domain : adam.com.au
Gateway : 1xx.xx.1.1 on Ethernet 0"

Please confirm!!!

Thanks,

Ganesh

Re: Changing the DNS settings may

John Steele — Fri, 10 May 2019 16:19:22 GMT

You only need to add/remove the PLM instance if the IP Address and/or hostname changed on the server it is referencing.

Re: [CUCM] Change DNS server IP

SaibhuwanSudina70631 — Tue, 05 May 2020 10:59:32 GMT

if changing the DNS IP leads to restart, is it only for cisco tomcat or the entire server.

please suggest where to find the path to cisco tomcat service..

Note : i am using 12.x.

Thanks & Regards

Re: [CUCM] Change DNS server IP

Syed491 — Tue, 14 Jul 2020 07:52:47 GMT

Hi,

Please find the path for tomcat.

Cisco Unified Serviceability--> Tools--> Control Center - Network Services

And you can do via CLI

Please rate helpful posts

Re: [CUCM] Change DNS server IP

lp.descamps — Wed, 16 Dec 2020 11:22:13 GMT

Hi,

I had few times this error "WARNING: DNS unreachable" on the cli after updating DNS.

The best approach for me to update DNS is to start with PUB, SUB then TFTP

replace the {{}} with your IP

delete dns {{CURRENT OLD IP DNS}}
delete dns {{CURRENT OLD IP DNS}}
set network dns primary {{NEW IP DNS}}
utils diagnose test
set network dns secondary {{NEW IP DNS}}
utils diagnose test

for example

delete dns 1.1.1.1
delete dns 2.2.2.2
set network dns primary 3.3.3.3
utils diagnose test
set network dns secondary 4.4.4.4
utils diagnose test

Re: Changing the DNS settings may

stanleychen21503 — Mon, 29 Aug 2022 07:40:06 GMT

12.5 no longer need it
https://community.cisco.com/t5/ip-telephony-and-phones/cucm-12-no-more-need-for-prime-license-manager-correct/td-p/3398334