UCM certificates

[gonzalezel]

We moved our voice environment to fully qualified domain names.  Since then I have multiple expired certificates callmanager-trust certficates where the common name is the host name.  However I have the new certificates where the common name is the fully qualified domain name that has a valid certificate.  Can I just delete the expired callmanager-trust certificates that are expired and keep the valid certs with the full fqdn. It seems like they do the same thing but I'm not very familiar with certificates. Thanks in advance.  For example:

Certificate	Common Name	Type	Key Type	Distribution	Issued by	Expiration
callmanager-trust	admssub1	self-signed	RSA	admssub1	admssub1	1/30/2018
callmanager-trust	admssub1.ad.johnson.com	self-signed	RSA	admssub1.ad.johnson.com	admssub1.ad.johnson.com	9/20/2020

[GadgetFood]

What version on CUCM are you running?
Did you regenerate the cluster?
We I updated UCM to FQDN I didnt have issue removing expired certificates I also did this during maintenance

Also see the below link which will give you so additional information on certificate regeneration and renewal
https://www.cisco.com/c/en/us/support/docs/unified-communications/unified-communications-manager-callmanager/200199-CUCM-Certificate-Regeneration-Renewal-Pr.html#anc13