MRA not working after upgrade to Expressway X12.5

[ruudvanstrijp]

Hi,

We have upgraded Expressway-C and -E from 8.11.4 to X12.5 in our lab, and since this upgrade MRA doesn't work anymore. Logging in is possible, we can see presence but Jabber does not register as a phone. We have tried this for two separate lab clusters, one running CUCM 11.5 and one running CUCM 12.5.

I haven't been able to go through the logs very thoroughly yet, but I was hoping someone on the forums has encountered this as well. Perhaps this is a known thing, especially since both my collague and me ran into this.

On the Exp-E, the Unified Communications status shows no errors, the UC Traversal Zone is active and the domains are detected properly.

A reboot of both nodes doesn't solve anything.

Regards,

Ruud

[Ratheesh Kumar]

Hi there

I came across a fix. Let me know if that helped

On Exp-C do a reverse DNS lookup on the IP address of Exp-E. Then flush the DNS cache of Exp-C to make sure it re-queries DNS properly.

Hope this helps
Cheers
Rath!

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[ruudvanstrijp]

Hi Rath,

Thanks a lot for your reply. Unfortunately your tip didn't solve the issue; I have done a DNS Flush (and even a complete restart of Exp-C and Exp-E) but this didn't solve it.

Regards,

Ruud

[ruudvanstrijp]

We have resolved the issue together with TAC. Apparently the Let's Encrypt certificate we used actually contained of two certificates:

1) The server certificate itself
2) The root certificate that signed the server certificate

This has always worked flawlessly (I found certs from mid 2018 that were the same way), but somehow X12.5 doesn't seem to allow this anymore. We split the cert up so it only contains the server certificate, and after this MRA worked again.

[Michael Rubin]

Thank you for this information.  It is very usefule trouble shooting tip.