If you are using a hosts file, make sure it contains FQDNs and pay close attention to the order in which they appear. Check the hosts file and adjust it if necessary: The FQDN must come first, followed by any aliases. /etc/hosts 10.0.0.1 server1.example.com server1 application1 If an alias is listed before the FQDN, you may encounter error messages that are not immediately traceable to this cause.