If I received a pong whose TTL is 0, is it means its ping was sent by me? Should I check the routing table (guid, socket) again?

you should not get packets with a ttl of 0

The ttl is decreased at a servent and after that if it is 0 it is dropped. So if you do get a ttl of 0 something went wrong and you could drop it (or use it for something, whatever you want)

Tam

If I received a pong with ttl = 1, am I the original sender of its ping? Or I should check it in my routing table again?

If you receive a ping with a Hop=0, one of your direct connected peer has send it to you.

About your question "ping was sent by me?"... you shouldn't receive a message from your own. Avoid loops to your own, don't connect to yourself! If you receive any message with TTL=0, you should drop the connection (as Tama said), because it's from a bad, broken servent. If you receive a message with TTL=1, you can say nothing about it, it just means "forward this message not anymore".

Well, there is more background and a little bit of pseudo code in this thread (you started it):
"Why do we need TTL?" - http://www.gnutellaforums.com/showth...&threadid=6363

/Moak

Thanks, very body!