Thanks... I believe your suspicions are correct. After the central host shuts down the rest of the network is still up and ready to connect. Unfortunately, the network I'm trying to do this on is too complex. There are many many broadcast addresses, and the network is very segmented that way. I'm trying the phex alternative, and while it keeps a network segmented and is cross-platform, it doesn't do any automated host discovery, even within the broadcast range. Anyone know an easy way to do this?

Here's the actual scenario: maybe people have some better ideas. I'm on a college campus, and we used to have an on-campus p2p network that was great (only campus sharing, no connection to the internet, so it was fast, and we didn't have to worry about the riaa and mpaa). Only problem was it used direct connect, which, by it's model, depends on one central host for everyone to connect to, and that facilitates searching, indexing, etc. of the files on the network. Problem with this was that it was easy as hell to shut down. Just cut off access to the central node hosting it all. So, I'm looking for a solution without central nodes to connect to. I know this is the idea behind gnutella, and that once I get the network set up, it should very difficult to shut down. (Yes, I know they could filter at the routers, cap bandwidth to certain ports, etc, but I'm not too worried about that now.) So my problem is that I want people to just be able to load up their client, maybe have to enter in one address, and just connect and not have to worry about it.

Help would be great! And don't worry about things being too complicated for me, I know exactly what I'm doing, I just don't know a whole lot about Gnutella. Thanks!

Restricting ports wouldn't be easy with phex, as every client sets a random port at first run.

You could setup some GWebCaches ( http://www.gnucleus.com/gwebcache/ or http://home.comcast.net/~jjulian16/ ) for which you set "supported networks" to the name of your college-network, download the phex-source ( http://sf.net/projects/phex ) and replace the preinstalled list of GWebCaches (simple text-list) with your networks ones (which should best be set to allow only connections from the College-LAN, but with a bit tweaking they won't allow connections from non-college-clients at all, and your connections won't see IPs of clients of another network whatever you do).

After compiling it, you can safely distrubute it. (You only need the GWebCaches for the first connection, then the program manages a local list of clients (the HostCatcher).

Still I would like to try a Mac-Port of Gnucleus, if you can do it. (You might want to pay a visit to http://gnucula.sf.net )

Phex has no special LAN functionality. All you can do is, like arne_bab described correctly, use a special network name and only Phex clients knowing this name are able to connect.

The LAN switch in Phex is only used to know if private IP addresses are accessible or not. Assuming you get search results with a private IP. Phex will try to connect to this IP if you are in a LAN, if not Phex will directly try to a PUSH. This optimization saves some time. So this is mainly a download and query optimization.

To find the initial connection point I would also recommend to use a or a few fixed GWebCaches or large host lists with only local IPs

Additionaly you could provide security restriction lists for IP ranges.

If you need help to provide certain special functions please contact me and we might be able to work something out that can go into the standard product too.

Gregor