Lots and lots of p2p programs exist nowadays, and you may encounter problems with them and just switch to an other or just give up.

Here’s a list and a some details about a few popular p2p programs:

BitComet/Other Bittorrent clients

The BitComet client is a P2P file-sharing program compatible with the BitTorrent protocol, one of the most popular P2P protocols designed for high-speed distribution of large files. BitComet supports simultaneous downloads selected downloads inside a torrent package along with fast-resume.

Direct Connect

Direct connect is a peer-to-peer file-sharing protocol. Direct connect clients connect to a central hub and can download files directly from one user to another.Hubs feature a list of clients or users connected to them. Users can search for files and download them from other clients, as well as chat with other users.

Emule/Edonkey

eMule is a peer-to-peer file sharing application for Microsoft Windows. Each file that is shared using eMule is hashed using the MD4 algorithm. The top-level MD4 hash, file size, filename, and several secondary search attributes such as bit rate and codec are stored on eD2k servers and the serverless Kad network.

Bearshare

BearShare is a peer-to-peer file sharing application originally created by Free Peers, Inc. for Microsoft Windows and currently sold by MusicLab, LLC. Three variations of BearShare were distributed by Free Peers: Free, Lite and Pro. The Free version had more features than the Lite version, but also contained some malware by WhenU. The Lite version was malware-free, but had fewer features than the Free version. The Pro version had more features than both the Free and Lite versions, but cost 24 dollars.

Problems that may POP-UP

The biggest problem at p2p programs that can appear is the connection problem, meaning that the applications can’t connect to hubs/servers/other users to download. In most of the times the connection problem is caused by firewalls that are blocking the ports that are needed to connect to the hubs/servers/other users.

You can find a great P2P Connection checker at http://connect.majestyc.net/ it works flawlessly, all you need to do is enter the TCP and UDP ports and it will check if they are open or blocked.

I found out about the tool from Peerweb DC++, because i was having some connection problems(this is why its good to read the troubleshooting guide)

You can find a list of TCP and UDP ports and the applications that use them at http://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers

If a port is blocked as stated above most probably your firewall is blocking the port. You need to set the programs permissions at your firewall/antivirus client.

Here’s how to do it if your using Kaspersky Internet Security(make sure the application is running):

Open up the control panel and navigate to firewall settings -> there go to rules for applications -> select your p2p program and click Edit -> Click Template and select the appropriate setting, or just press Allow all