On Running Tor Relays
When I first learned about the Tor Project in late 2000's, I immediately wanted to contribute. There are many ways for individuals to contribute to the project such as through donating, volunteering, or by telling your friends and family about the project. One of the ways I chose to contribute is by running a Tor exit node. Before I go into my experience and recommendations in successfully running an exit node, I'd like to cover some basic terminology. In general there are three types of relays or nodes:
- Tor Relay: These hosts are the backbone of the Tor network. They act as an entry point into the network and they pass traffic between relays as well.
- Bridge relays: These relays act just like regular relays, but are not published in the public Tor directory
- Exit nodes: In addition to acting like a Tor relay, they also act as a last hop (or exit) for the Tor network
For those who are unfamiliar or would like to contribute by running a relay, I would recommend beginning with either a regular Tor Relay or a Bridge. Both of those choices are safe because they will not allow any of Tor's traffic to exit through your node. The relay will simply increase the overall bandwidth and host diversity of the overall Tor network.
Once you've had some experience running a Tor relay or Bridge for awhile, I would encourage you to consider running a full-fledged Exit node. From my personal experience, the switch was relatively painless and seamless. As long as you follow project's recommended practices, you should be able to run one with minimal issues.
In order to reduce and/or eliminate the number of complaints you may receive, you should consider running a reduced exit policy. Exit policies are a way for Tor to limit what ports/protocols can exit through your node. You can find a recommended reduced exit policy on the project's website. This exit policy covers some of the most common ports/protocols that have a low likelihood of being abused by a malicious actor.
I would discourage you from running a wide open Exit node, as you will likely run into issue rather quickly. When I first started runnin an Exit node, I decided to runa wide open policy. This resulted in me receiving 17 DMCA complaints after a week of running the node. Once I switched to a reduced exit policy, I never received another complaint from my ISP.
Many ISPs and companies do not explicitly deny Tor, but it is always a good idea to check their Acceptable Use Policy or Terms of Service to ensure you are not violating any rules. In reviewing these policies, you should search for sections specifically prohibiting the running of a "proxy" or other network services.
If you cannot find anything specifically prohibiting Tor, you should take a look at the community maintained list Good/Bad ISPs. If your ISP or hosting provider is not on the list, then you should contact them directly for clarification on running an exit node.
From my personal experience of running an exit node on and off for the past ~3 years, the biggest challenge is just to ensure you keep your tor server up-to-date. Running a responsible exit node will likely not land you in hot waters, though you should still educate yourself on the possible legal consequences. Here are a few supplemental articles that I'd recommend you review:
The aforementioned articles should assist you in understanding many possible scenarios that you may need to deal with as a relay operator.
One interesting thing I've found from running an exit node, is where you choose to run it matters. The Tor project does not recommend volunteers to run relays from your own home/residence because of the issues it can cause. Now if you choose to do so, you will find out that the web becomes a little more restricted. Many network and service operators actively monitor for known Tor exit nodes and may either temporarily or permanently ban your IP address. Some of the more notable companies that do this are: Yelp.com, Craigslist.org, 4chan.org, Google Search & Maps, and CloudFlare. If maintaining access to these websites or companies are important to you, then I would recommend that you not run your exit node and/or relay from home's Internet connection.
In closing, the Tor project depends entirely on volunteers to provide network capacity to the Tor network in order to serve the ever increasing demand it has. If you can spare the cycles, I'd recommend that you consider running a relay. If you have any other questions about becoming a relay operator, feel free to contact me or the Tor Project directly.