[tor-relays] High conntrack session count

[Zack Weinberg]

On Wed, Jan 4, 2017 at 8:05 AM, Sec INT <sec.int9 at gmail.com> wrote:
>
> Just had an issue on a 60mbps exit where conntrack sessions went over the usual 30000 limit - is this possible for a normal operating exit relay? Is there any default limit set on this or indeed is there a setting intorrc to control the number of sessions?

Yes, it is perfectly normal for an exit to have tens of thousands of
active TCP sessions.

An exit doesn't get a lot of use out of a firewall.  Your only sockets
listening to the public network (netstat -lnt) should be Tor, SSH, and
the "this is an exit" page on port 80.  fail2ban-type protection for
the ssh port *may* be worth it, but I don't see what you would need
conntrack for.

zw