What port-range in the firewall of a Socks (e.g. JSocks) server?

Question

Hi there,
I am using the JSocks implementation of a socks v5 server.
Some of my questsions are quite general (not only specific to JSocks) and I hope that someone knows the answer. Unfortunately the forum of JSocks (sourceforge) is only rudymentary so I think this place is better to answer my questions.
However...
As I understand the socks proxy, the server waits on a specific port - normally 1080 and processes the client requests (bind, connect, accept...).
For example one client requests a bind. Then the socks server opens a port locally on the socks host and (if successful) replies the new listening port and ip to the requesting client. ...
(Forget authentication, cascaded proxies and ip-ranges at this point!)
Now, if other clients should be able to access this port, the firewall (if any) needs to allow connection to this port.
My questions:
What should be an adequate port range for the socks proxy? With other words: what is the port range of the new ports that are created for the requesting clients?
How schould a seperate firewall be configured not to conflict with a socks proxy?
Specific to JSocks (if somebody knows this he wins a virtual cookie): What is the port range that JSocks uses if it opens (generates) new ports for its clients?
Where is the port range defined in the jsocks - I havent found any?
Imagine that on the same machine there are other running applications that are listening on predefined ports. (e.g. 8080, 21, ...) - what is the best way to exclude the ports in jsocks?
Any hints and explanations are welcome!
Edited by: krafzig on Oct 28, 2008 8:27 AM

Answer 1

You only need one port.OK, initially I need only - lets say port 1080.
But then for example a client c1 requests a bind. The socks server opens a new socket for the client (e.g. on 50000) and tells the client on which port on the socks he is now listening, right?
In order to allow client c2 to connect to this new port the firewall needs to allow access to the new port (50000) first.
So there are more ports - there might be hundrets or thousands, right?
If its on a seperate box it doesn't matter. If its on the same box it should manage different ports.yes, different ports!
However, it should allow access to the ports that the socks opens for the clients, right?
Optimal would be a dynamic adaptation of the firewall, whenever the socks opens a new port the firewall grants access.
I assume its configurable, so its up to you.No, unfortunately it is not configurable. At least I havent found anything.
Probably won't either.???
Don't use ports already used. `netstat -a` will list all the used port on that box. obviously, and Jsocks allows to configure reusage of ports by flag true/false;
Has anybody setup a socks proxy with a firewall and knows how this is/should be done normally?
Has anybody experiences with JSocks?