[standards-jig] My IP Address

Michael Brown michael at aurora.gen.nz
Sun Sep 7 07:49:01 UTC 2003

>Justin Karneges schrieb am 2003-08-27 17:04:26:
>> What about a simple way of asking the server for the client's own IP
>> address?  
> It's not the first time, that this is proposed.

Because it's a great idea ;-)

> I don't like it (personally). If the user is able to configure port
> forwardings on the NAT router, he is also able to install 
> a SOCKS proxy there.

That is not even close to true.  I know how to configure port
forwarding on my NAT box.  I challenge you to come over
and get a SOCKS proxy working.  It's one of these:


Seriously.  With broadband becoming more and more
popular, most people are going to have a NAT box in
their house.  And believe me, the majority won't be
Linux boxes.

> I don't like the idea of the server telling the IP address 
> because that may fail as well if there is address translation 
> or forwardings on the server side. On amessage you 
> won't get anything usefull if you ask the server for the IP 
> of the client, it would always give you local server IPs.

Surely that is a solveable problem though.  The server has to 
be able to work out the IP address somehow (?)

> I expect you want to use it for file transfers. It's a good 
> intension to try as much as possible before you try to 
> transfer the file through the server. 

Yes - for this you need the external IP address.

> But on the other hand I think that we can get to 
> many different ways a file transfer can be configured. 
> It may be that you ask Joe Average to much if he has
> to decide which file transfer standard he wants to use,
> where he wants to get his IP and so on.

Exactly.  This is the point.  We need a simple, standard
and reliable way to get the IP address.  Asking the server
is the best option.  (Unless you have another suggestion)

The otherway is to make an HTTP call to a server - 
this is what we do in Yabber, but the problem is that
many ISP's have transparent proxying on port 80, so
the returned IP address may be the proxy machine.  I 
doubt very much that they will bother proxying port 5222
so this is the best solution IMO.


PS - Mattias, can you set your email client to not send
messages as attachments?  It is a pain to have to read them
in Notepad.

More information about the Standards mailing list