Agents aren't using the primary server's valid DNS name

Agents trust the primary server only if they contact it at one of the valid hostnames specified when the primary server was installed.

On the agent node, if you don't get one of the primary server's valid DNS names (which you chose when installing the primary server) when you run puppet agent --configprint server, then the agent node and primary server can't communicate.

1. To edit the primary server's hostname on agent nodes, open the /etc/puppetlabs/puppet/puppet.conf file, and change the server setting to a valid DNS name.
2. To reset the primary server's valid DNS names, log in as root (or the Administrator) and run:

   puppet infrastructure run regenerate_primary_certificate dns_alt_names=<COMMA-SEPARATED_LIST_OF_DNS_NAMES>