CUCM subscriber node failing authentication on IM&P servers

[@Syed]

Hello All,

Hope you are all well!

I have recently added CUCM subscriber node to the cluster and everything is working fine excepted cluster authentication between new node and IM&P servers. I get the below error on running the " show network cluster" command.

192.168.x.x CUCM04.xyz.local CUCM04.xyz.local Subscriber unknown unknown not authenticated - INITIATOR since Mon Jul 6 08:15:09 2020

Note: this is happening only on IM&P servers

[Nithin Eluvathingal]

what's the output  of "show network cluster" on CUCM publisher. 

Check connectivity  between IM and Subscriber.  

[@Syed]

Thanks for reply.

As I mentioned CUCM network cluster status is all good.

[@Syed · Accepted solution]

I have found the problem.
Following TCP ports are allowed unidirectionally on the firewall between IM&P and CUCM and that fixed the problem
Port Direction: CUCM > IM&P
8500 TCP
5060 TCP
2555 TCP

[Nithin Eluvathingal]

Great..

if there is a  firewall in-between, its always better to check  below link.

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/12_0_1/systemConfig/cucm_b_system-configuration-guide-1201/cucm_b_system-configuration-guide-1201_chapter_01010110.html