Running Tor on a v-server with limited number of TCP sockets

Mike Perry mikepery at
Wed Feb 21 21:09:33 UTC 2007

Thus spake Stephan Walter (stephan at

> On 2007-02-21 21:25, Alexander W. Janssen wrote:
> > From a pragmatic point of view that would also mean that you wouldn't
> > be able to log in from remote if TOR gobbles up all sockets.
> It's not as bad as that, as the ssh daemon is listening all the time and
> therefor already has its socket.

Actually, it probably is as bad as that. Each time accept() is called
on this server socket to handle a new SSH connection a new socket is
formed.. Unless their limit has a special exemption that they coded
themselves for accept().. But most likely its some garbage usermode
Linux thingy with ulimit -n set on the usermode linux process.

On the plus side, if they did code this exception for accept(), it
should apply to Tor as well, at least for incoming connections to the
OR port.  Eventually most routers should connect to you, and Tor will
just use those OR connections (though they may get closed if no
circuits are on them.. not sure about how long Tor keeps idle OR
connections open).

However, my scanner (if it ever works :) probably will end up flagging
your node as unreliable.. But you've got a while before that actually
means anything.

Mike Perry
Mad Computer Scientist evil labs

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