[LAU] Even more netjack trouble (although setup seems as described)

Jörn Nettingsmeier nettings at folkwang-hochschule.de
Tue Sep 28 10:42:15 UTC 2010

On 09/28/2010 12:30 PM, Julien Claassen wrote:
> Hello Jörn!
> So no matter if he initiates the connection, he will also need the
> correct ports forwarded from his router?

UDP is stateless, and there is no concept of "initiating a connection" 
on the network layer. you basically send a UDP packet and hope it makes 
it. the opposite end does the same.

so say we have this setup:

machine A:
router A: internal address, external address x.x.x.x
router B: internal address, external address y.y.y.y
machine B:

router A must listen to the UDP port you want to use and forward each 
packet to machine A.
router B must listen to the same port and forward to machine B.

say you're A. your partner host will then be y.y.y.y, i.e. the router. 
since it's forwarding, you will be in effect talking to machine B.
same rules apply for the other direction.

it's advisable to run a testing tool for udp connections before you try 
netjack. i recommend iperf, it's text-mode and available at sourceforge 

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