[tor-relays] blocking >1 connections per ip address onto Tor DirPort

[Felix]

Hi everybody

 >>> Does a particular Tor server/client will open more than 1
 >>> connection at a time from to the DirPort ?

 >> If you're worried about denial of service issues on the DirPort,
 >> maybe the simple answer is to turn off the DirPort? I think the
 >> only real impact might have something to do with whether old
 >> clients believe that you're a usable guard.

 > understood - removed those iptables rules

Good discussion. My experience is protecting the dirport makes
sense to avoid ddos attempts.

During my Debian times this rule worked fine for me:

/sbin/iptables -A INPUT -p tcp -d $IPEXT --dport 80 -j ACCEPT
-m limit --limit 5/s --limit-burst 50


On FreeBSB I go with something like:

pass in on $IFEXT inet proto tcp from !<blockDIR> to $IPEXT port 80
flags S/SA keep state (max 150,max-src-states 50,max-src-conn 50,
max-src-conn-rate 20/10,overload <blockDIR>)

# release the blockDIR after some hours
pfctl -t blockDIR -T expire 7200 # hourly cron job


-- 
Cheers, Felix