Hello All, I commented and questioned earlier about significant slowing of one of my Finnish exit relays [1] and potential DoS attack. I took the server off line and did the best job I could hardening it. The host does not have DoS protection and uses Xen OpenVZ as his VPS manager. I was getting "nf_contract: table full, dropping packet." errors by the 1000s. That's fixed and I'm back on the Tor net now. One question remains: At any time I look there are 20-150 Iranian IP addresses trying to access the Tor server. Their IP range is from 5.113.x.x to 5.126.x.x. None have hashed fingerprints. Is it okay to let these guys go? Can they harm or slow Tor? Should I ban them? I'd like to learn from this. -potlatch
Sent with [ProtonMail](https://protonmail.com) Secure Email.
Hi,
On 16 Aug 2019, at 04:22, potlatch potlatch@protonmail.com wrote:
One question remains: At any time I look there are 20-150 Iranian IP addresses trying to access the Tor server. Their IP range is from 5.113.x.x to 5.126.x.x. None have hashed fingerprints. Is it okay to let these guys go? Can they harm or slow Tor? Should I ban them? I'd like to learn from this.
This is probably a connection error caused by Iranian censorship.
We're working on anti-censorship and stats fixes, but I can't find the tickets right now.
In the meantime, try using a lower value for Tor's DoSConnectionMaxConcurrentCount option. The consensus value is 50, but you should set your value based on the number of connections from a single IP address. Or just try 25, then 12, ...
If no single IP address is problematic by itself, you can use a firewall to limit the number of connections, or the new connection rate, from an entire address block.
T
-- teor ----------------------------------------------------------------------
tor-relays@lists.torproject.org
-
potlatch -
teor