Symptoms:
User tries to rlogin to a machine in some other domain and is refused with a "Permission denied" type error message.
Possible Cause:
To rlogin to a machine in another domain, a user must have LOCAL credentials in that domain.
Diagnosis:
Run nismatch username.domainname. cred.org_dir in the other domain to see if the user has a LOCAL credential in that domain.
Solution:
Go to the remote domain and use nisaddcred to create a LOCAL credential for the user in the that domain.