Jump to content

Multiple computers - same uTorrent port?


harper

Recommended Posts

I have a small home network and use Utorrent on 3 computers.

I have to enable port forwarding through my router.

Should each machine use a different port for uTorrent or is it fine to have all three machines using the same port.

If all three machines are running utorrent at the same time could this create a problem?

Thanks!

Link to comment
Share on other sites

Different ports, and it'll work fine so long as you don't choke your bandwidth with all of them running. Since you registered today, an additional note, if two or more computers are downloading the same thing, because of Local Peer Discovery the computers should detect each other and share with each other, this happened on my own network when a family member and I both started the same torrent, data either of us didn't have was shared.

Link to comment
Share on other sites

If you intend to use all three utorrents at the same time most of the time its recommended to set to speedguide to 1/3rd of you real upload each of the clients. This is to prevent connection chocking (results in slow web browsing, timeouts, problems with other programs that use internet, etc)

Link to comment
Share on other sites

Hi, thanks for the replies.

I do not intend to use it on all three machines at the same time but this is a rare possibility.

I understand my bandwidth would be shared between the three machines and the need to limit my upload speed on each machine.

But would it cause a conflict having all three use the same port. Ie. port 49156 and port forwarding to all three IP addresses.

Thanks again.

Link to comment
Share on other sites

It's technically impossible and you might mess up the router. Either that or it will mirror all the traffic all over and cause a lot of wasted bandwidth. Anyway, setting up different ports shouldn't be that hard, and even if it takes time it should still be done.

Link to comment
Share on other sites

Port forwarding requires one port to be tied to a specific IP address. Just assign a unique fixed port number on each computer. Then forward those port numbers to the appropriate computer in your router. Go to portforward.com if you need step-by-step instructions.

Link to comment
Share on other sites

  • 4 years later...

Just came across this 4 year old thread when searching for an answer to this very question.

If anyone happens to read this I have some more questions: ok so you can't forward the same port to multiple machines, hmm, but multiple machines on a LAN use the same port for similar applications, ie. I bet all three of his PCs had a web browser installed using port 80... sooo, why is it not a problem generally, but it is a problem once data on port x is forwarded to a specific IP? I'm guessing NAT is taking care of it but not fully understanding that I don't know how. I get what GTHK said about all the traffic getting sent to all the IPs on the LAN if that port forward to multiple IPs were possible, is this not happening with port 80 traffic all the time? If not why not? And if not, why does a port forward rule have to be set up manually in the router to take care of whatever port uTorrent is using but it doesn't have to be set up for HTTP? What would happen if you forwarded port 80 to x.x.x.x and there were multiple computers behind the router (I will play about with this myself but don't have time today)?

Thanks.

Link to comment
Share on other sites

Web browsers do NOT use port 80, web SERVERS use port 80 for listening, browser connect to the server (port 80) on what are called dynamic or private ports, which are unassigned ports in the range 49152 to 65535, when a browser initiates a communication with a web server it make a request to the OS it is running on for the next available private port and uses this in the packets it sends out to port 80 of the server it is requsting information from. The port you open for torrent clients is listening port (incoming requests) and no two devices on a single network cannot be listening on the same port as the router has no way of knowing WHICH IP to route the packets to.

Link to comment
Share on other sites

Ok I see.

Wow really, no 2 devices in the same network can be listening on the same port. So that must be problematic at times I'm guessing, like if you have multiple SQL servers in the same LAN, do some of them have to be configured to listen on different ports?

My uTorrent port at the moment is somewhere up in the 6 thousands, as you say, this private port range is between 49152 to 65539, how does my OS know not to assign the port that uTorrent is using?

Link to comment
Share on other sites

Nope maybe i should have worded it differently, but it is somewhat more technical than that.

You can have mutiple devices within the same network, using the same port PROVIDED the communication to that port does not have to be routed from an external source. If you do not need to manually port forward through your router because of NAT routing (Network Address Translation) which is basically "automatic port forwarding", TCP/UDP packets for that port will be passed to the internal IP that is listed in the routing table. So two IPs for one one port will simply not work.

Most domestic routers are not NAT capable simply to keep costs down.

When the OS assigns a private port, or an application or service requests a particular port, it is flagged as in use by the OS so it cannot be given to another service,

Skype can cause problems for web developers who run a development web server on their machine, because by default Skype listens on :80 and :443, which are assigned to HTTP: and HTTPS: respectively, so when you try to start a web server it fails because the ports are already in use.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

×
×
  • Create New...