Hello everyone!
You might recall that Tor is restricting the possible amount of Tor relays per IP address to 2, mainly for Sybil prevention reasons.[1] Given that Tor on the relay side at least is not multithreaded yet (and will likely not be for the near and medium future) that's wasting a lot of useful resources as many servers can easily handle more than 2 relays. Additionally, IPv4 addresses are scarce/expensive.
I have good news for you, though. Thanks to a push by our relay operator community we raised that limit to 4 with the help of the directory authorities (by having set `AuthDirMaxServersPerAddr 4` on a majority of them) and, depending on how that experiment goes, consider raising it even to 8.
Thus from now one should be able to run 4 relays per IP address. We are looking very much forward to seeing a bunch of additional relays entering the network and making it stronger. :)
For more details, information and discussion see: tor#40744.[2]
Thanks, Georg
[1] https://gitlab.torproject.org/tpo/core/torspec/-/blob/main/proposals/109-no-... [2] https://gitlab.torproject.org/tpo/core/tor/-/issues/40744