Troubleshooting Tor

There are a number of reasons why Tor might not function properly. A few of the more common issues are described here, along with suggested solutions. Before proceeding, make sure that all four programs included in the Vidalia bundle are installed and working properly. All of the functions described in this section are accessible through the Vidalia Control Panel.

Note: One of the best ways to ensure that newly installed Windows software is working properly is simply to reboot your computer. A surprisingly large number of common errors can be resolved this way!

4.1 How to View the Message Log

Any time Tor is running, even while it is attempting to make its initial connection, you can view its log messages. This can help you establish whether the software is working and, if it is not, what might be causing the malfunction.

Click:

The Message Log that appears will look similar to Figure 13.

Figure 13: The Vidalia Message Log

This log shows that Tor has started. It will continue to display messages about how Tor is functioning. You should not be overly concerned about the 'experimental software' warning. Despite what it says here, Tor is the most well-tested anonymity tool available. There are a few important error messages that you should watch for, however, if you are having trouble with Tor:

• connection_create_listener(): Could not bind to 127.0.0.1:9050: Address already in use. Is Tor already running?

This means that another Tor process has already began. The simplest solution in this instance would be to shut down Vidalia and restart the computer.

• Vidalia was unable to start Tor. Check your settings to ensure the correct name and location of your Tor executable is specified

This error occurs when Vidalia cannot find the Tor executable file, tor.exe. Search your computer for this file and specify its location in the General tab of the Vidalia Settings window.

• I have learned some directory information, but not enough to build a circuit

This message may appear repeatedly while Tor is first starting up, and may continue to appear for quite some time if you have a very slow Internet connection. It simply means that Tor is still downloading information about the anonymity network.

When Tor is ready for you to use it, the log will will display the following message:

• Tor has successfully opened a circuit. Looks like client functionality is working.

Figure 14: Tor has successfully connected message

This message indicates that Tor has established a path through its network and appears to be functioning correctly. If you are using Firefox, you still have to enable Torbutton before you can browse websites anonymously. If you are using some other application, you must configure its proxy settings so that it connects to the Internet through Tor.

If the log has failed to produce new information for fifteen minutes, after displaying an 'Opening Control listener' or 'Tor has learned some directory information, but not enough to build a circuit' message, then you might need to adjust Tor's network settings. It is possible that your current Internet connection requires you to use a particular Web proxy or that it blocks certain ports. It is also possible that your government or ISP has begun blocking access to the Tor network.

4.2 Tor's Network Settings

There are a few steps that you may need to take if you find that Tor has stopped working properly or if it fails to connect when you first install and run it. Try changing the network connection settings related to proxies, ports or Bridge Relays, as shown below.

Step 1. Stop the Tor service in Vidalia.

Step 2. Open the Vidalia Settings screen.

Step 3. Click:

Figure 15: The Settings screen in the Vidalia Control Panel

When you are done with these settings, click the OK button to close the Network Settings window, then Start the Tor service in Vidalia.

4.2.1 Using a network proxy

If you are required to use a proxy server to access the Internet, then specify its details in this window. In general, this is more common on company and university networks, but proxies are occasionally required at Internet cafes, or even nationwide in some countries. If the necessary proxy information is not clearly posted, you may have to ask a network administrator or someone else who is using the same Internet connection.

Step 1. Check the I use a proxy to access the Internet option.

Step 2. Enter the proxy details into the fields provided:

Figure 16: The proxy details section

4.2.2 Port restrictions

Some network or computer settings may restrict access to certain ports. If you can browse websites normally, then you can rely on at least two ports (80 and 443) being accessible. You can set Tor to work exclusively through these ports.

Step 1. Check the My firewall only lets met connect to certain ports option.

Step 2. The Allowed Ports field should already display '80,443', as shown in Figure 17 below:

Figure 17: The Firewall Settings section specifying open ports on the network

4.2.3 Using a Bridge Relay

If you still cannot connect to the Tor network, two options remain:

Option 1: Refer to the Tor FAQ wiki for suggestions.

Option 2: You may reside in one of the few countries that block Tor on the national Internet. In this case, you need to use a Bridge Relay to access Tor.

Bridges allow you to access the Tor anonymity network, even if it is blocked from within your country, by providing a hidden 'first step' into the network. In order to use this feature, you must provide Tor with the location of at least one Bridge Relay. Ideally, you should enter three or more Bridge addresses. If you know and trust someone who is already using a Bridge, you can learn this information from them. Or, you can use one of two methods supported by the Tor Project's Bridge Database. First, you can send an email to [bridges |at| torproject |dot| org], from any Gmail account, with the words "get bridges" in the body of your message. The database will reply with addresses for three bridges. (Remember, you should only ever log into your Gmail account using the https://mail.google.com address!) As an alternative, you can visit the Bridge Database website at https://bridges.torproject.org/ (while not using Tor) and it will display information about three different bridges.

Note: The Bridge Database is designed to prevent anyone from easily learning about all of the Bridges, so it may appear to advertise the same Bridges each time you ask. If you let enough time pass, it will eventually provide new information.

Step 1. Check the My ISP blocks connections to the Tor network option.

Step 2. Type or Paste a Bridge address into the Add a Bridge field. As shown in Figure 18, Bridge information will include an IP address and port number, such as 79.47.201.97:443, and may also include a long string of letters and numbers at the end, such as 80E03BA048BFFEB4144A4359F5DF7593A8BBD47B.

Step 3. Click:

Step 4. Repeat the above steps for each additional Bridge address. It is recommended that you enter at least three.

Figure 18: Inserting a Bridge Relay Address

4.3 Uninstalling the Vidalia Bundle

To remove all packages installed as part of the Vidalia bundle, perform the following actions:

Step 1. Select Start > Programs > Vidalia Bundle > Uninstall

Step 2. Choose a language for the installer and click Next

Step 3. Check All three of the packages shown in the window

Step 4. Click Next then click Uninstall.