Cisco ISE Queue Link Error

[Netmart]

Hello,

We did receive the following alert:

Queue Link Error: Message=From ISE-Node1 to ISE-Node2-ISE-1.mskcc.org; Cause={tls_alert;{unknown_ca;"tls Client:

In State Certify At Ssl_handshake.erl:1887 Generated Client Alert: Fatal - Unknown Ca\n"}

What has been checked so far:

1) Service: Running at both nodes

ISE Messaging Service                  running          20704

2) Port is open at both nodes: show ports

     tcp: 0.0.0.0:15672, 0.0.0.0:8671, 0.0.0.0:8672

3) Cert validity check

Jun 16 2022  - Jun 17 2027

Jun 24 2024 - Jun 25 2029

Version: 

Cisco Identity Services Engine

---------------------------------------------

Version      : 3.1.0.518

Build Date   : Mon Aug  9 16:28:55 2021

Install Date : Fri Jun 17 07:29:59 2022

Cisco Identity Services Engine Patch

---------------------------------------------

Version      : 3

Install Date : Fri Jun 17 08:13:40 2022

Any advice is much appreciated.

[marce1000]

  - FYI : https://community.cisco.com/t5/security-knowledge-base/ise-queue-link-error/ta-p/4625179

  M.

[ahollifield]

https://www.adamhollifield.com/2022/09/fix-cisco-ise-messaging-service.html

[Aref Alsouqi · Accepted solution]

The error you are getting is stating "Unknown CA" which requires regenerating ISE root and ISE messaging service certificates as per the link shared by @marce1000. In addition to the above link please check this video at minute 5:41:

ISE Messaging Services and Queue Link Errors

[netmart2]

Thank you Aref.

This video worked for me: regenerating ISE root and ISE messaging service certificates fixed the issue.