What's the point of UseDNS?

[Dan Mahoney, System Admin]

According to the manpage:

UseDNS Specifies whether sshd should look up the remote host name and 
check that the resolved host name for the remote IP address maps back to 
the very same IP address.  The default is ``yes''.

Thing is, while sshd *checks*, this doesn't actually control whether or 
not the client is allowed to connect, it seems at most to be an option 
that causes additional logging.

Is there some option that actually lets me control connection based on 
this?  Perhaps display a message to the connecting host as to the problem?

-Dan

-- 

--------Dan Mahoney--------
Techie,  Sysadmin,  WebGeek
Gushi on efnet/undernet IRC
ICQ: 13735144   AIM: LarpGM
Site:  http://www.gushi.org
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