Adding a 2nd Tor node on the same Pc

Question

I have been running my Tor node since July 2016 and I have been reading the emails on the [email protected] with interest, sometimes confused as to what they are talking about. It was suggested that you can safely run two Tor nodes on the same Pc. Question.....do I install tor exactly the same way but call it a similar but different name, use the same orport 443?, and use the same contact details. Also adding the Family details as well, which I understand is important. If some one can talk me through the steps I need to take to add a 2nd Tor relay please.......and have i missed anything out that should be there.

Thanks in advance

Steve

Answer 1

Yes, it's not uncommon for people run two relays on a single server in cases where bandwidth isn't the bottleneck, to take advantage of two CPU cores (since much of Tor's functionality is locked to a single core, running two can increase throughput).

If you're not currently using up an entire CPU core for just one Tor instance, then it may not be worthwhile for you to do this. One faster relay is probably more helpful than two slower ones on the same IP.

Under the Tor project packages, for systems that use systemd (most modern Linux distributions), there is a tool distributed with it called tor-instance-create which can create multiple Tor instances. If this is available, the process will be much more simple.

tor-instance-create second # replace "second" with whatever you want the instance to be called

This will create a new systemd service entry, a new /etc/tor/instances/second/ folder that contains the torrc for the second instance and a new /var/lib/tor-instances/second for use as the DataDirectory.

Edit the torrc, ensure that you use different ports for each relay, to avoid conflicts then run the commands

systemctl enable tor@second
systemctl start tor@second

You should now have the second Tor instance providing a relay.

You should, as a courtesy, set the MyFamily lines in each to include each others fingerprints (they don't need their own, they just both need to have the relay fingerprint for the other). You can find their fingerprints under /var/lib/tor/fingerprint and /var/lib/tor-instances/second/fingerprint respectively.

If you're not using a Debian derived Linux distro then you'll need to set this up manually, you'll need to look at whatever system daemon management software it's using and create a new entry for the second relay.

The important points for setting it up are:

1. They both need to use different DataDirectory folders, otherwise they will conflict and cause problems.
2. They both need to use different ports, for all services (you may need to specify SocksPort 0 on the second's torrc, to avoid it trying to use the default of 9050).
3. Setup MyFamily using the fingerprint found in the fingerprint file in the Tor instances DataDirectory, each relay should contain the fingerprint for the other relay (although it doesn't hurt to add it's own too).

Other than those points, you should be fine.

Answer 2

Well, strictly speaking, Tor does filters the "too much nodes on one IP" and "too much nodes from one subnet" cases, so - there're two parts of the answer:

• Yes, you can run even 10 nodes on one PC, it's just a question of CPU cores and RAM: disk usage is very tiny and even a SATA-II HDD will handle 10+ relays simultaneously
• No, you should not run two/multiple relays on one external IP, because they will be filtered out

What you need is either a second ISP link with different IP, or a VPN to provide you a different IP for each extra relay

As an addition - make the relays exclude each other in their torrc configs, so the effect for the network will be maximized