I am using archlinux and i am unable to use azureus because the first 1024 ports are blocked for normal user. My isp blocks all other ports except a few in the first 1024(20,21,22,81 etc) so i can't use any other port. i installed firestarter and unblocked port 81 but no effect for non-root user. i get permisson denied when i do the firewall test but everything works fine as root. also when i test another port beyond 1024 i get the nat error and not the permission denied error. A firewall test(shields up) shows that every port except 81 is stealthed as it should be. I have no idea what's wrong.

The first 1024 ports on any *nix system are considered privileged and only the superuser can bind to them. I thought that there was a sysctl somewhere that could change this, but grepping around I don't see it right off. However, this article gives some other ideas to work around this which you might be interested in. Using iptables to redirect incoming port 81 to some other port looks like a good solution. I would not run azureus as root through sudo, unless there's some way it can be made to drop privileges after it has bound to the port.

If you use a NAT router, you may be able to translate the port in the routers setup. It may be referred to in the router setup as port triggering.

I just figured that port 5000 and 6000 are opened by my isp, so i am using those.