[tor-relays] Limiting connection count

[Moritz Kammerer]

Hi,

I'm running a Tor relay on a Raspberry 2 behind a router using port
forward. Relay bandwidth is set to 1 MByte / second. Tor is accepting so
many connections that my Raspi can't keep up and my router is getting
very slow (I assume because of a crappy NAT implementation). Bandwidth
is not an issue, its the open connection count.

Is there a way to limit the maximum number of connections? I tried to
apply a ulimit on open files via systemd, but Tor is then showing a warning.

At the moment I run a iptables rule which restricts the connection count
to port 9001 (OR port) to 1000. But I'm not sure how this will affect
the relay, for example Tor Metrics is showing the relay as offline.

BR, Moritz