I read through the gnutella specs and it was a little hard to understand how a leaf should handle pings and pongs, it seems the section about pings and pongs is more foces at how ultrapeers should handle them. so my questions are:
1) Do Leaves cache pongs? I was reading on the Limewire site that the Limwire leaves don't cache pongs
2) Pongs should have the IP's and Port's of Ultrapeers, so what IP and Port should a leaf put in a reply pong if it doesn't cache pongs?


Any help would be appreciated!

Ultrapeers - Leaves

This architecture's goal is to push the weak peers outside the network, and let the strong ones to mediate between them and the enitre network.

Leaves are not part of the network so they have no reason to cache pongs,
pongs caching is used in order to decrease the network traffic (leaves are not part of it)

- Leaves are connected to Ultrapeers
- Ultrapeers are connected to Leaves and other Ultrapeers

Ultrapeers creates and sends PONG packets (from their cache!) to their leaves to make sure their ultrapeers list is fresh and updated.

The bottom line - Leaves shouldnt receive pings
(and If they do - its just a way of an Ultrapeer to ask "Are you alive?", and in that case - its obvious you put your own IP , port in the PONG packet)

2) No, PONG packet contains your own IP and PORT, As I said - Ultrapeers creates PONGS of other ultrapeers from their cache.