WARNING: DNS unreachable

[Muhammadnawaz]

Hi everyone,

We have an issue since the activation of license on primary CUCM,  initially the secondary CUCM was coming up with this warning message as mentioned in the title and below. now this warning message appears on both Primary/Secondary CUCMs. please suggest the solution to fix this issue as we have tried to restart the CUCMs also reinstall the license but still the issue is same.

Primary:

Secondry:

Thanks in advance for support.

[Muhammadnawaz]

Also please comment about this issue we got on the CUCM, even both CUCMs are in cluster but still it is showing the warning message like this (WARNING: No backup device is configured. This is required to recover your system in case of failure). 

thanks for experts opinion. 

[Nithin Eluvathingal]

Add a backup device and take backup.

2.12.0.0

[Dmytro Benda]

Hello, 

BACKUP Warning - to remove it, you have to configure Cisco DRS. It is a connection to SFTP server for your CUCM back up. 

Here is a guide how to configure DRS:CUCM DRS configuration guide

As for your DNS issue - can you ping your primary DNS server from your Publisher CUCM CLI? 

My Cisco Unified Communications Blog

[Muhammadnawaz]

Hi Dmytro,

thanks for the comments, yes am able to ping primary DNS server from the publisher. 

[Dmytro Benda]

Hi @Muhammadnawaz 

Ok, please read this post too:

https://community.cisco.com/t5/ip-telephony-and-phones/cucm-warning-dns-unreachable/td-p/2714928

Isn't it your case? 

My Cisco Unified Communications Blog

[Nithin Eluvathingal]

 Am you check the forward and reverse lookup for the cucm nodes ?

[Muhammadnawaz]

Hi Nithin, 

thanks for the help, I check the diagnostic on both CUCMs Reverse Lookup is failed and output is as follows..

[Nithin Eluvathingal]

Add reverse entry/ PTR RECORD on your dns and that solve the issue

[Nithin Eluvathingal]

Check both forward and reverse lookup if its working.. it could be because of the Reverse lookup. I have seen this most commonly when  reverse lookup fails.

issues the below command from CUCM CLI

utils diagnose test

2.12.0.0