[p2p-hackers] Unidirectional or Bidirectional Manual Port Forwarding?

[David Barrett]

coderman wrote:
> On 8/17/05, David Barrett <dbarrett at quinthar.com> wrote:
> 
>>1) Are manually-forwarded NAT port mappings typically unidirectional or
>>bidirectional?  Does this depend on the NAT model?
> 
> This is NAT specific behavior / implementation dependant.  What you
> describe is not uncommon, since UDP is stateless many NAT's lazily
> assume that port forwards operate in one direction.

Gotcha.  Good to know; I'll redesign with that in mind.


>>2) Is it possible to manually configure the outbound mapping (ie, force
>>all traffic originating from an internal endpoint to use a specific
>>external endpoint)?
> 
> You can do this with Linux NAT's and probably others, but I doubt
> D-Link will be cooperative.  Just to verify, the internal IP:port is
> using the same port as the one configured in the nat to forward
> traffic to, correct?

That's correct.


> You may want to dig around on some game sites about UDP port forwards
> with the D-Link device you are using.  There are some multi-player
> games which rely on loose UDP NAT or port forwards and they may have
> some insight into the particular problem you are experiencing.

Ahh, that's a good tip.  Thanks!

-david