Behind a firewall? Seeing a yellow light all the time? Slow speeds?

Figure out what you have, and try these methods to get your BitTorrent client working optimally.

Forward the BitTorrent Ports To Your Computer

Most hardware firewalls (such as firewall routers) have the capability for port forwarding. If you are running a software firewall (such a ZoneAlarm or BlackIce), then portforwarding is probably called something else, like "Application Internet Permissions" or somesuch. The BitTorrent client will normally use ports 6881 to 6889, so when you are adding the ports to your firewall, make sure you cover the whole block. Many newer BitTorrent clients have larger or changeable port ranges, so check with the instructions for your client software first. For most of these instructions you will need to know what your computer's IP address is. Under Windows NT, 200, and XP, go to Start >> Run >> type cmd and click OK >> at the prompt type ipconfig and press Enter. Under Windows 95, 98, or Me, go to Start >> Run >> type winipcfg and press Enter.

Linksys
Netgear RT314
Netgear RP114
USR Broadband Router
Linux IPTables
Shorewall for Linux
Linux ipmasqadm
Windows Firewall

Linksys Firewall Router

Access your Linksys Firewall Router's web admin page, according to the instructions in the manual for your router. You will probably need to enter a password. At the top of the web page there is a series of navigational links, and you want the one that says "Advanced". From there, move on to "Forwarding". Find an empty row in the form on that page, and fill in the name ("BitTorrent"), the port range (6881 to 6889), check the TCP box, and set the IP address to the one that your computer is. Check the Enable box then click the Apply button to save the changes.

What's important here is that the port range matches what's in your bittorrent client, and that you put the last octet of your desired computer's IP address (your internal IP not the IP your ISP gives you!) where those ??? are. Apply it however you are supposed to and run a torrent to see if your light is now green.

Netgear RT 314 (and possibly other models)

Access the web administration interface. Then click Advanced in the menu to the left, then click Ports. Use an empty row (everything is zero) and enter in the first column ("Start Port") 6881, in the second column, enter 6889, and the last one, enter the IP address for the computer running BitTorrent. Click the Apply button, and you're done

Netgear RP114

1. Under Windows NT, 200, and XP, go to Start >> Run >> type cmd and click OK >> at the prompt type ipconfig and press Enter. Under Windows 95, 98, or Me, go to Start >> Run >> type winipcfg and press Enter.
2. 'IP Address' is the address of your PC, 'Default Gateway' is the IP address of the router
3. In Internet Explorer (or another browser) type the IP address of the router into the address bar.
4. Enter in your name and password. (Defaults are 'Admin' and '1234')
5. Go to 'Advanced' >> 'Ports'
6. In the "Start Port" and "End Port" fields enter the port range (6881 to 6889), and in the "Server IP Address field" enter in the IP address of your PC. Apply.

USR Broadband Router

On the USR router, it's an option in the web-based config tool. The option is called "Virtual Server" and you enter the port and the IP of the virtual server for it to forward. (The computer running BitTorrent.)

Linux IPTables

iptables -t nat -I PREROUTING -p tcp --dport 6881:6889 -j DNAT --to-destination <host>
... where <host> is the private or internal IP actually running the BT client.

also, this seems to work well for some people:

$IPTABLES -t nat -A PREROUTING -i $EXTIF -p tcp --dport 6881:6889 -j DNAT --to 192.168.1.50
$IPTABLES -A FORWARD -i $EXTIF -o $INTIF -p tcp -d 192.168.1.50 --dport 6881:6889 -j ACCEPT

Shorewall for Linux

For systems that are using masquerading (NAT) and have something like the following:

In /etc/shorewall/masq:

# All outgoing traffic from 192.168.1.X going out the eth0 interface
# will be NATed/masqueraded to appear to be originating from your external
# internet address A.B.C.D (i.e. SNAT outgoing packets)
eth0 192.168.1.0/24 A.B.C.D

And in /etc/shorewall/rules:

# Allow net zone traffic on the external interface to be destination NATed (DNAT)
# to your computer's internal IP address (for example, 192.168.1.X)
# Allow BitTorrent traffic through - port 6969 is if you run a tracker
# And ports 6881 through 6889 are for incoming BitTorrent connections.
DNAT net loc:192.168.1.X tcp 6969
DNAT net loc:192.168.1.X tcp 6881:6889

Linux ipmasqadm

ipmasqadm portfw -f (flushes all other rules.. optional)
ipmasqadm portfw -a -P tcp -L [firewall IP] 6881 -R [client IP] 6881

WindowsXP Firewall

To open the ports around windows or norton firewalls [if you use norton, you can also exclude ports the same way through the options feature]:

1. Go to your control panel

2. Click on Window security center

3. Click on the bottom "windows firewall"

4. Click on the second tab called "exceptions"

5. Click "add port"

6. Create a name like "BT outgoing 1"

7. Enter the BT port "6881" in the port box.

8. Once you've entered that information, you will have to continue to open all the bt ports manually.

9. You should have manually opened ports 6881-6889 or you can even go up to port 6899 [again this is for modems only]

10. It requires a little time and repetition but once you've opened your bt ports you should always get a green light.

11. When you are done, you will see several "bt outgoing 1, bt outgoing 2.....etc with each port assigned. [make sure the boxes are checked and you are done].

These solutions were copied from various lists and pages from other helpful people.

if you have specific solutions for any particular brand of firewall, router, or modem, please contribute! Make a post on the forums. Please be as specific as possible, and including pictures sure doesn't hurt!