FAQ

5.1 Does µTorrent work well on Windows XP SP2 systems with an unpatched TCPIP.SYS?

Yes, as of version 1.2, µTorrent will do 8 connection attempts by default to work with the 10 connection attempt limit on these systems.

Patching tcpip.sys to a higher value may help if you are having problems (such as trackers timing out when they're actually online), though setting it higher than the default may cause some routers to have freezing problems. If you would still like to patch it, you can do so with LvlLord's EventID 4226 Patcher.

However, you should never set it higher than 50! net.max_halfopen should ALWAYS be set lower than the value you patched tcpip.sys to.

5.2 Help! µTorrent is sending e-mails/accessing the web/ etc!

This is a false positive 99% of the time. Occasionally, peers use common service ports, such as 25, 80, and so on to bypass restrictions they may have on their ISP. You should ALLOW this traffic, not block it! You may have to turn off the firewall's/anti-virus' e-mail protection, or set an exception for "utorrent.exe". The only exception to the false positive rule is on start-up, where µTorrent loads a page on uTorrent.com to check for the latest version. You should also allow this. This functionality can be disabled in the General section: "Check for updates automatically."

It also connects to router.utorrent.com if you have DHT enabled. This is REQUIRED for the functionality of DHT (at least the first start). If you block it, DHT may not function!

To put it simply, a false positive means that your firewall is WRONG.

5.3 My firewall is reporting connections being made by µTorrent on a port besides the one I selected. What gives?

Only incoming connections use the port you selected in µTorrent. Outgoing connections use a random local port; this is simply the way TCP/IP functions. It's not a bug.

If you have a firewall, you must allow all outgoing traffic on TCP and UDP.

5.4 How do I change the number of connections µTorrent uses?

Go to BitTorrent and set "Global maximum number of connections" and "Maximum number of connected peers per torrent."
See this important note on this setting.

5.5 What do the Network Status lights mean (, , )?

The green light means all is OK (ports are forwarded and you are receiving incoming connections)
The yellow light means that you have no current incoming connections. If this never turns green, this means that your port is not forwarded. The best way to check is with the µTorrent port checker, found in the Speed Guide. If the port checker says your port is open, then everything is most likely fine.
The red light means that µTorrent was unable to bind a listening socket. Most likely, this means a firewall is blocking it. It's also possible that another torrent client is using this port, which will require you to change ports, or not run both clients at the same time.

5.6 Why are my torrents going so slow?

Most likely, the port you set for µTorrent is not forwarded. If µTorrent is displaying , then this is the case. There is also the possibility that the torrent is simply slow, especially those with small swarms (low numbers of seeders/peers). It is also possible that your firewall is blocking connections for µTorrent. Make sure you set an exception for incoming and outgoing connections for µTorrent in your firewall's configuration! If you block ICMPs with your firewall (Windows Firewall blocks them by default), you should allow "Destination Unreachable" to aid the proper functioning of DHT (it works anyway though).
If everything is set up fine, you will see in the status bar (to the left of DHT:) after you start a torrent and get an incoming connection. If it stays yellow, try a torrent with many peers to make sure there's enough peers in the swarm to guarantee you getting an incoming connection.

If you use an alternate firewall while on Windows XP SP1 or SP2, make sure you turn off the Internet Connection Firewall (SP1) or the Windows Firewall (SP2).
You may still have to disable the Internet Connection Firewall (ICF) or Windows Firewall / Internet Connection Sharing (ICS) service to prevent a conflict between it and your third party firewall. Control Panel -> Administrative Tools -> Services, scroll to appropriate service (ICF or Windows Firewall/ICS), right click and select Properties, select Disabled in the drop down menu and hit OK.

If you have an alternate firewall and still find yourself unconnectable after you forwarded your ports (or have no router) and attempted to configure the firewall, you may need to uninstall it, disabling never works! If you have no router and no firewall, your modem may be a router.

You may also want to turn off UPnP (found in Connection) and forward your ports manually, since some routers have flaky UPnP implementations that cause problems. Ensure your router/modem is NOT on this list!

Make sure you've used the Speed Guide and read the instructions carefully! Make absolutely sure you chose your UPLOAD speed in kilobits/s, not your download! Make sure you do not set too many upload slots OR connections per torrent. You should also try to never run more than 2-3 torrents. In general, an average 5mbit connection with 512kbit upload shouldn't have more than 90 connections per torrent, or more than 5 upload slots, especially if running more than one torrent. Experiment with these values depending on your connection speed. This is the most COMMON reason for torrents going slow, setting those options too high WILL make things slow down significantly! More connections does not mean faster speeds. Your best bet is to stick to the Speed Guide.

Make sure that TCPIP.SYS is properly patched if you've altered net.max_halfopen, and that net.max_halfopen is set lower than the value set in TCPIP.SYS! And ensure that it's still patched, because Microsoft overwrites it sometimes, forcing you to repatch.

5.7 How do I forward ports?

This is beyond the scope of this FAQ, but PortForward should have the information you require. TCP forwarding is required at minimum, UDP is only used for DHT at the moment. You can verify if the forwarding works on BTFAQ's NatCheck. It requires you to have a torrent running, however. Alternatively, if you are on Windows XP/2003, or are using 1.5.1 beta 462 or later where UPnP works on all OSes, and have a UPnP enabled router, you can use this to forward ports automatically. This is considered a security risk by some, however. If does not disappear, make sure your firewall is not blocking incoming connections for µTorrent.

5.8 What ports should I use for µTorrent?

It is generally recommended to not use any port in the range 6881-6889. µTorrent only uses one port, however, so you only need to forward one. It is best to use a port number above 10000.

5.9 How do I change the port µTorrent uses?

Open the Options, click Network. You can change the port in the box next to "Port used for incoming connections." However, it takes a restart of µTorrent to take effect. Make sure you do not run two clients with the same port!

5.10 Does µTorrent support proxies?

Yes. Open the options and go to Connection. It supports SOCKS4, SOCKS5, HTTP Connect, and HTTP proxies. Peer communication proxying is supported with SOCKS4, SOCKS5, and HTTP Connect. HTTP Connect is HTTP proxies that allow arbitrary TCP connections. Not all do, which is why it's a separate item in the list.

5.11 Does µTorrent have a scheduler to limit download and upload speeds?

Yes, in the options. It allows you to set an upload/download speed, and set it to Limit, go full speed, or stop torrents altogether by the hour/day. You can also make it turn off DHT during hours you set to "Turn off."

Version 1.4.1 beta 417 and later have a new scheduler mode for Seeding only. Hold shift while selecting the hours and it'll turn red, which indicates seed-only mode.

5.12 How can I make µTorrent use a different upload speed when seeding?

Open the options, go to Connection, check "Alternate upload rate when not downloading", and write in the value you would like in the box.

5.13 How can I make µTorrent report a different IP to the tracker? I'm behind a proxy and need this function.

Go to BitTorrent and put in the value in the box next to "IP to report to tracker." It supports IPs and domains as of 1.3.1 beta build 374. This function is NOT for when you are behind a NAT, the tracker can automatically determine your IP in that case. It's only when your WAN IP (as in, the actual internet connection's IP) is different from what the tracker sees. However, some trackers WILL ignore this value, so it may not help you at all.

5.14 How can I make µTorrent use a specific network adapter?

In the Advanced section, you can specify the IP for the adapter. net.bind_ip specifies which adapter to use for incoming connections, and net.outgoing_ip specifies which adapter to use for all outgoing communication.

5.15 How can I change the number of active torrents/downloads?

Open the options, go to Queueing, and change the values for "Maximum number of active torrents (upload or download)" and "Maximum number of active downloads"