There are a number of reasons why Tor may not function properly. A few of the more common issues are described here, along with suggested solutions. All of the functions described in this section are found on the Vidalia Control Panel.
Note: A surprisingly large number of common errors can be resolved by simply restarting your computer, or by re-extracting the Tor Browser Bundle.
You may view the Tor log messages even while it is attempting to establish an initial connection to the Tor network. The log messages can help you determine if the software is working properly, and if not, the cause of the problem.
Step 1. Click to activate the Message Log screen, and then click the Advanced tab to display a screen resembling the following:
Figure 1: The Vidalia Message Log
This log shows that Tor has started. It will continue to display messages about how Tor is functioning. Do not be overly concerned about the experimental software warning; despite its message, Tor is the best and most thoroughly tested anonymity tool available.
However, there are some important error messages that are critical if you are having trouble with Tor; a few are described below.
This message indicates that another Tor program has already been started. The simplest solution in this instance would be to close all running Vidalia programs or restart the computer.
This message indicates that the Vidalia program cannot locate the Tor executable file, tor.exe which appears as follows: . To resolve this problem, perform the following steps:
"Step 1. Restart your computer and try to run the Tor Browser again. If the error persists, perform Step 2:
Step 2. Delete the current Tor Browser folder, then download the latest version of the Tor Browser Bundle. Extract the Tor Browser Bundle, and then run it."
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 in the process of downloading necessary information about the Tor network to establish a Tor circuit or connection to your system.
When Tor is ready, the message log will display the following message in Figure 2 below:
Figure 2: A message confirming a successful connection highlighted in dark blue
This message indicates that Tor has successfully established a path through its network and appears to be functioning correctly.
Note: Even if you are using Mozilla Firefox, you must enable Torbutton before you can anonymously surf the Internet. If you are using a different browser, you must configure its proxy settings so that it connects to the Internet through Tor.
If the message log fails to produce new information after fifteen minutes or so, and even after displaying an Opening Control listener or a Tor has learned some directory information, but not enough to build a circuit message, then you might need to adjust the Tor 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.
If you find that Tor fails to connect when you first install or run it, or that it has stopped functioning properly, changing the network settings may fix the problem. The network connection settings are related to proxy server, ports or bridge relays, as discussed in this section.
Step 1. Click in the Vidalia Control Panel to stop Tor.
Step 2. Click to activate the Settings window.
Step 3. Click to view the Settings window in Network mode as follows:
Figure 3: The Settings window in Network mode
Step 4. Click to accept the settings and close the Settings window, then click in the Vidalia Control Panel to start Tor.
If you are required to use a proxy server to access the Internet, then specify its details in this window. In general, proxy servers are more common on corporate and university networks, but proxy servers are occasionally required at Internet cafés, 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 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 4: The proxy settings section
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 configure 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 5 below:
Figure 5: The Firewall Settings section specifying open ports on the network
If you still are unable to connect to the Tor network, two options remain:
Option 1: Refer to the Tor FAQ wiki for suggestions.
Option 2: If you reside in one of the few countries which actively blocks Tor from accessing the Internet, you may need to use a bridge relay - or bridges for short - to establish a connection to the Tor anonymity network.
A Tor bridge allows you to access the Tor network - even if it is blocked from within your country - by providing a hidden 'first step' into the network. To use this option, you must provide Tor with the address of at least one bridge. Ideally, you should enter three or more bridge addresses. If someone you know and trust is already using a bridge, you may ask them for this information.
Alternatively, you may use one of two methods supported by the Tor Project Bridge Database.
Method 1: Send an email to [bridges |at| torproject |dot| org], from any Gmail account, with the words "get bridges" in the main text 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!)
Method 2: Close the Tor program and go to the Tor Project Bridge database website https://bridges.torproject.org/, and it will display information about three different bridges.
Note: The Bridge Database is designed to prevent anyone from easily learning all of the bridge addresses; at first, it appears to to advertise the same bridges each time you ask. After enough time has passed, however, it will eventually provide new addresses.
Step 1. Check the My ISP blocks connections to the Tor network option.
Step 2. Cut and paste or type a bridge address into the Add a Bridge field, as shown in Figure 6. Bridge information will include an IP address and port number, such as 188.8.131.52:443, and may also include a long string of letters and numbers at the end, such as 80E03BA048BFFEB4144A4359F5DF7593A8BBD47B.
Step 3. Click to add the address into the pane beneath the Add a Bridge text field.
Step 4. Repeat steps 2 and 3 for each additional bridge address; it is recommended that you enter a minimum of three; to enter more, you may have to wait a while for the bridge database to refresh itself.
Figure 6: Adding a Bridge Relay Address