On Fri, 27 Dec 2013, Dan Mahoney, System Admin wrote: > I think the point here is that there's no option for openSSH to then > *drop the connection* or refuse it. OpenSSH *checks*, but does not > *enforce* anything. That's not entriely true. from=... restrictions in authorized_keys and "Match host" sections in sshd_config depend on the hostname. In the reverse-mapping check failed case, they don't get to see the original (probably untrustworthy) hostname and are just passed the IP address. Basically, the things that depend on the hostname will not be shown one that appears spoofed. -d