Is it possible to query freeradius' certificate expiration remotely?

Is it possible to query freeradius' certificate expiration date remotely for the cert in /etc/raddb/certs? I'm trying to set up an alert so there's notification when the cert is <60 days from requiring renewal. I'm trying the following but the command returns connection refused on all of the ports I expected it to work on: openssl s_client -servername rad2.domain.com -connect rad2.domain.com:1813 | openssl x509 -noout -dates I've tried ports 443, 8080, 88, 1812, 1813, 1645, 1646, and everything else I can find that might be listening, to no avail. Thanks for any guidance /mh