P2P in VB.NET

I recently built a small Remote Administration Tool in VB6.0 with a few controls using Winsock. How hard is it to send a actual File from one application to another in VB.NET?

Fairly simple. Look into TCPClient/TCPListener and/or network streams.

That would probably be the easiest route to do it. Or perhaps remoting. You will have to deal with synchronization issues (as happens to all network programs), but it makes life pretty easy.

Im not quite understanding a P2P. Lets say I wanted to build a P2P program for people just to share MP3 and Music files. Would a person connect to one main server or network to see other users files?

P2P stands for peer to peer. It means the network is a mesh of peers, each connected to eachother. A client-server aproach means every client connects to a server.

In reality, there are very few networks taht are truly peer-to-peer. The reason for this, if it is public, is the need for "discovery" of other peers. If you don't know where the other peers are, its impossible to join. Therefore, most networks are hybrid. You connect to some sort of server to get address of peers, which you then connect to. Those peers can give you more addresses to connect to. In reality, the servers are only needed to bootstrap the network and get the peer in contact with one other.

hmmmm...interesting.

In most networks like Gnutella/2 there is a main server that holds your ip address, port, and username, etc. When you connect to the network and search for a file, the server looks through all of the other connected user's shared folders for matches and will return the URL of that file and will connect you to that person. When you start downloading a file, most networks bypass the server and go straight from user to user while some may monitor and filter out certain downloads. The truth is that a central server is not necessary BUT will make the whole process alot easier. Otherwise you will need to know the ip address of wherer you want to download from, that would be more like FTP.