If you can't ping an ip address since you are not resolving a canonical name this has nothing to do with dns and only has to do with the inability to reach that machine (routing) right?
You are correct in that if you ping an IP address you are not using DNS. If you are using a hostname instead of an IP address with
ping, then you will be using DNS.
However, just because you are using
ping with an IP address, even if you don't get a response this does not necessarily mean there is a routing problem. Many hosts are configured to rate limit ICMP echo requests (i.e. ping) or to ignore them entirely.
"PING" on a Windows 7/8 machine will attempt to perform a "Reverse DNS" lookup on the IP address before attempting a PING. It's reverse DNS because you are doing the reverse of what DNS natively does, i.e. resolve a name to an IP address. But that is just a feature to help identify what you're pinging.
PING still uses the IP address to formulate its echo request. The inability to perform the reverse DNS does not preclude the ICMP echo request to be sent, nor does it prevent the echo reply to come back if there is one.
Hope this helps.