Hi there, I just notice that in limewire there is a pane called "monitor Incoming Searches", and when I enable this function, I curiously notice that they actually work, I can see the query send to my pc.

But if I am not wrong, I remember that now limewire are using a technic called ultrapeer instead of the traditional broadcasting way, that is to say, when I login into limewire network, I should upload my shared file to those ultrapeers, ultrapeer should remember my shared files, but why there are still query packets send to my pc?

oops, I missed sth, “I should upload my shared file to those ultrapeers” should be I should upload my shared file INFORMATION to those ultrapeers,

"The Query Routing Protocol (QRP for short) is an essential part of the Ultrapeer specification: it governs how the Ultrapeer will filter queries and only forward those to the leaf nodes most likely to have a match. This is done without even knowing the resource names, by looking the query words through a big hash table, that is sent by the leaf node to its Ultrapeer.
The aim of the QRP is to avoid forwarding a query that cannot match, it is not to forward only those queries that will match."

QRP

Thank you rkapsi.

Does this means ultrapeer will not keep the EXACT shared files informtion of all the peers connect to it?

That is to say, when a peer connect to a ultrapeer and initiate a search request, the ultrapeer will transfer the search request to some of its clients, ultrapeer itself will not do any search work?

Right. And the Ultrapeer receives at no time "the EXACT shared files information", only a table of hashes.

Right. Well not quite, computing the Hash from the incoming queries, looking into a Hash Table and forwarding the queries to the appropriate clients is also some kind of "search work". But all this is described on the page I gave you (see also the link on the top of the page).