Windows Firewall

LimeWire automatically adds itself to the list of exceptions in the Windows firewall (assuming that the firewall is enabled and an exception does not already exist) when you launch the program. The Windows firewall should not need to be configured. If for some reason, you need to open up a port in the Windows firewall manually or add an exception for LimeWire, or you just want to check and make sure that LimeWire has been added, you may visit the Windows XP Firewall Instructions page.

By default, the OS X Tiger firewall is turned off and should not need to be configured. If for some reason, you need to open up a port in the OS X firewall manually, here are instructions for doing that:

1. Go to LimeWire > Preferences > Advanced > Firewall Config, and make a note of the listening port located in the box next to "Listen on Port"
2. Go to System Preferences > Sharing > Firewall
   • On older versions of OS X, go to System Preferences > Internet & Network > Sharing > Firewall tab
3. Click the "New" button and select "Other" next to "Port Name"
4. Enter the TCP and UDP port numbers as specified in LimeWire's settings

Some modems and routers contain firewalls. A router is a device that allows multiple computers to connect to the internet through one connection while at the same time connecting each computer to an internal network. If you are using an external modem to connect to the internet, it would be plugged into the router, and the router would be plugged into the computer or transmitted wirelessly. Most routers are UPnP-enabled and should not need to be configured. If you are using an older router that does not support UPnP, you may need to set up manual port forwarding, or if the router uses a firewall that is blocking the connection, you may need to open a port for LimeWire.

Within the LimeWire options (accessible from Tools > Options on most systems), go to Advanced > Firewall Config, and locate the listening port. Open this port in your modem's or router's firewall for both incoming and outgoing connections, UDP and TCP.

This section applies to those who receive the following error message when LimeWire launches:

LimeWire was unable to initialize and start. This is usually due to a firewall program blocking LimeWire's access to the internet or loopback connections on the local machine. Please allow LimeWire access to the internet and restart LimeWire.

When LimeWire loads, it checks to see if LimeWire can talk to itself (ie - make loopback connections). If it can't, then a security program is likely blocking LimeWire. Check any security programs installed on your computer to make sure that LimeWire is listed as an exception. Norton's Internet Worm Protection feature has been known to cause LimeWire to produce this error.

• If you have never been able to connect, contact your Internet Service Provider (ISP) to find out if they block peer-to-peer connections. Some ISPs block or limit peer-to-peer traffic in order to reduce the burden on their servers. Also ask if you are connecting through a proxy. ISPs that provide high-speed-like connections through normal dial-up connections use proxies, and many satellite connections also use proxies. LimeWire will need to be configured to work with your proxy by going to Advanced > Proxy within the LimeWire options. If your ISP sent you a modem, ask if it is equipped with a firewall.
• If you have been able to connect in the past, the existing exceptions in your security program(s) may have stopped working. Remove all exceptions for LimeWire in all of your security programs, and then re-add them.
• If you are trying to connect from school or work, then you are probably connecting through a Local Area Network (LAN), and you may need to contact the system administrator to make sure that a network firewall is not preventing LimeWire from connecting to the Gnutella network.