New Servant Identifier

lapsy · #1 (**permalink**) May 18th, 2008

Can someone please let me know, how a gnutella client obtains its servant identifier? Is it randomely generated or is it some hash function of its ip?

AaronWalkhouse · #2 (**permalink**) May 18th, 2008

It's random.

lapsy · #3 (**permalink**) May 18th, 2008

If it's randomly generated then what stops a peer from stealing the servent_id of another from?

arne_bab · #4 (**permalink**) May 19th, 2008

Gnutella Protocol Development

Quote:

Last 16 Servent Identifier. A 16-byte string uniquely identifying the
responding servent on the network. This SHOULD be constant
for all Query Hit messages emitted by a servent and is
typically some function of the servent's network address. The
servent Identifier is mainly used for routing the Push
Message (see below).

Nothing stops you from that, but it doesn't gain you that much either.

You might be able to steal push messages intended for a leaf connected to the same UP, but that doesn't do much damage.

Gnutella worked quite well, when some clients had far too weak servent IDs, so it shouldn't be too much of an issue. And if it becomes an issue, I can already think of some solutions (like the UP informaing the leafs that they have the same servent id and they switching due to that).

If you're writing your own client, it MUST be completely random, though. And the random function should return good randomness (you need only calculate this once).

lapsy · #5 (**permalink**) May 19th, 2008

thanx a lot.. i guess that solved my problem

arne_bab · #6 (**permalink**) May 20th, 2008

Glad to hear that!

Besides: The new Gnutella specification is available at GDF - LimeWire (that's a relay subdomain, so the specs can change the place and still stay accessible from that domain).