A quick way to check your network for IPs missing reverse DNS entries…. nmap -PE -sP 10.0.0.0/24 | awk '{if ($2 ~ /^[[:digit:]]/ ) print $2}'

Why is there no subdir inside .ssh called authorized-keys.d where I can just throw my ssh keys and easily manage them by file name instead of having to edit the authorized-keys(2) file? I need to do some googling on this , a quick search yields this debian bug report on wishing for support for one.