trouble with low-numbered port number and tracker

[lloyd]

Hi, I don't know whether or not this should be a bug report.  I thought I'd post it here as a question first, and it can be moved to bugs if it is a bug.

I can't use port for hosting games 42424 because my ISP will not open that port for incoming connections, so I want to host games on a low number port, say 81.  My idea is that the tracker (which I understand runs on port 42420) will provide my IP and the non-standard port number to players who want to join.  At least, I think it SHOULD work that way.

When I set port 81 by starting with "d2x-rebirth -udp_myport 81", when I go to multiplayer to host a game, when I get to "Start game" I immediately get the error message "Can't bind name to socket."

I am doing something wrong or is this a bug?

[zico]

Usually lower numbered ports serve a problem as they tend to be used or reserverd for other services. I am not sure if there is a permission or restriction on the OS level but mostly the usable port numbers start at a 4 digit number. I am not aware that this is a probelm in DXX but I might be wrong actually - I never got lower ones to work. DXX is also set so it does not "reuse" ports - it will demand one which is not used and not reserved.

Tracker will have no problem with that. Tracke ronly uses 42420 outgoing on your end - so your ISP cannot screw this up.

I'd say check around for more common applications that use some higher port numbers and try one of those.

[Trent Hawkins]

So wait. Tracked games can now be hosted on IP other than 42424?

[zico]

Sure. You can run your games on ANY FREE PORT and it'll work on the tracker. Always have been like this. Your game will report itself VIA the tracker port (which is always 42420) and the tracker will list it with the port you selected (if that port is open that is).

[Trent Hawkins]

Interesting. I was left with the impression that 42424 was only working for tracker. My bad on miss-informing people. Thanks.

[aqqman]

The game has no problems working on port 81 - tested - both 57.1 and 57.2 (not on my connection )
The "Can't bind name to socket." error happens usually when your OS is using it and doesn't allow any other applications to use it. Try any other ports lower than 1024 (which could require some tricks under linux - irony: and some say that windows is trying to be smarter than the user)

[v66r]

to bind to ports below 1024 you have to be root.

[zico]

Hah - I knew it was somethign like that.
Do you have any source on that, v66r?

[v66r]

It's some historical unix background, maybe quite obsolete but still common according to this article:

http://www.staldal.nu/tech/2007/10/31/why-can-only-root-listen-to-ports-below-1024/

Don't know how windows handles this - if you have to be SYSTEM or in the Administrators group...

[Trent Hawkins]

I just did a quick test hosting a game on port 1 (without opening it) on windows 7. Aside from tracker not responding the game ran fine; no fail to bind name to socket or anything... Just a quick reply... Don't know what really happens in the background, it would require some search.

[zico]

Yeah I guess the permissions thing only affects UNIX-based systems.