Hi,
Based on the information I have (missing some pieces but should be ok), you should do the following:
1. Go to CWMS Administration > Settings > Security > Certificates on CWMS System.
2. In Internal SSL Certificate section, click on More Options > Generate CSR (certificate signing request)
3. Populate the needed information and complete the process.
4. Download the CSR.zip file.
5. Extract this file as it will contain csr.pem and privatekey.pem file. (privatekey.pem file keep somewhere safe and don't share with anyone).
6. Use csr.pem file and reach out to any Public Certification Authority (Verisign, GoDaddy, Thawte, etc.) and purchase a SAN SSL cert based on the CSR you will provide them. Based on my SSL checker run it seems you have 50 user system with only Admin and IRP VM in the solution, so you should need the SSL cert for these:
Common Name: - it will be Admin Site URL (meetingsadmin.video.zorlu.com)
Subject Alternative Names: - it will include FQDN of the Admin VM (wmsm.video.zorlu.com), Admin Site URL (meetingsadmin.video.zorlu.com), and WebEx Site URL (meeting.video.zorlu.com)
7. Once Certification Authority issues you the SAN SSL cert based on your CSR, and provides you with their Intermediate SSL certs, you can proceed to create an SSL cert bundle file based on the information in this article: https://supportforums.cisco.com/t5/collaboration-voice-and-video/cwms-ssl-certificates-intermediate-ssl-cert-chains-and-different/ta-p/3138702
8. Once you have SSL cert bundle file created properly and you are ready to install it, go to CWMS Administration > Settings > Security > Certificates on CWMS System, click on Import Certificate
9. Browse the the SSL cert bundle location and select the cert bundle you created (no need to enter any passphrase), and upload it.
10. Once uploaded the system will be placed into Maintenance Mode.
11. Click Continue and Done to complete the SSL cert upload process.
12. Finally, go to CWMS Administration Dashboard and turn OFF Maintenance Mode.
13. Once the system comes out of MM, you can use this link: https://www.sslshopper.com/ssl-checker.html#hostname=meeting.video.zorlu.com to confirm that the system is now using proper SSL cert and all looks in good order. From that point on you shouldn't see any certificate warnings when accessing WebEx Site URL or joining meetings.
P.S. Your version of CWMS is rather old and vulnerable to many defects, so I would suggest updating it at least to 2.8 MR1 Patch 2. This is the order of updates you must do:
1. 2.6 > 2.6 MR3 update
2. 2.6 MR3 > 2.8 base (2.8.1.17)
3. 2.8 base > 2.8 MR1 (2.8.1.1023)
4. 2.8 MR1 > 2.8 MR1 Patch 2 (2.8.1.1070)
All these updates are considered minor updates so you can follow the documentation for minor updates: https://www.cisco.com/c/en/us/td/docs/collaboration/CWMS/2_8/Administration_Guide/cwms_b_cwms-administration-2-8/cwms_b_cwms-administration-2-8test_chapter_01000.html#task_16A8E168CF7A4DAFBEBDA284BE3213BF
NOTE2: Before running any update, always put the system into Maintenance Mode, do a graceful shut down of the VMs (in vCenter: Power > Shut Down Guest), take VM snapshots on each VM, power them ON which will boot them in Maintenance Window, and then start the update. When the update is completed successfully, make sure to DELETE VM snapshots from all the VMs to avoid performance issues. Info on how to take and remove snapshots can be found here: https://www.cisco.com/c/en/us/td/docs/collaboration/CWMS/2_8/Administration_Guide/cwms_b_cwms-administration-2-8/cwms_b_cwms-administration-2-8test_chapter_01.html#task_A0F5735130C245A0B22E30BFF3161337
I hope this helps.
-Dejan
