The created module file that the user can load to enable the cluster has an entry of the form
setenv LOCALDOMAIN "ec2.internal <clustername>.pcluster "
This needs to prepend the existing user domain otherwise an access to a machine that is in the user's existing domain will not resolve.
Assume I'm in example.com and the above is set. If I try to ssh to "host1" I will get an error. I need to ssh host1.example.com for it to work. If I update the above to be:
setenv LOCALDOMAIN "example.com ec2.internal tsi4.pcluster tsavoritesi.net"
the ssh and other non-FQDN hostname references to hosts in example.com will resolve.