$ssh2->check_hostkey(Net::SSH2::LIBSSH2_HOSTKEY_POLICY_ASK(), "d:/profiles/known_hosts.pub") 
    or $ssh2->die_with_error ;

##</code><code>##

$ssh2->check_hostkey('advisory', "C:/Cygwin/home/user/.ssh/known_hosts") 
    or $ssh2->die_with_error ;