This version of the Kerbros/GSSAPI support avoids DNS lookups
for Kerberos-related names. These DNS lookups were problematic
for dialup users because they would lead to excessive delays
if DNS was not reachable.

In order to disable these lookups, I had to change the default
configuration, disabling GSSAPI authentication.

If you do use Kerberos, please make sure you edit the server and
client configuration files as follows:

/etc/ssh/sshd_config:

	GSSAPIAuthentication yes
	GSSAPICleanupCredentials yes
	
/etc/ssh/ssh_config:
	Host *
	    ... lots of other options ...
	    GSSAPIAuthentication yes
	    GSSAPIDelegateCredentials yes