Re: [lwip-users] routing over PPP using lwip

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Hi Sylvain,

> Hi Ajay,
> 
> What you are looking for is a NAT[1] implementation, not basic IP routing[2], 
> lwIP does not provide NAT at all. There used to be a basic NAT feature merged 
> in, but it was removed because the one who proposed the patch wasn't allowed 
> to do so.
> 
> NAT, other than basic NAT support, is a huge task. Especially for tricky 
> protocols (FTP, SIP/RTP, …) which require well designed helpers. I'm not sure 
> it qualify as being added in a lightweight stack.
> 
> Sylvain
> 
> [1] https://en.wikipedia.org/wiki/Network_address_translation
> [2] https://en.wikipedia.org/wiki/Packet_forwarding

I am probably misunderstood IP_FORWARD switch of LwIP. Sorry for being silly 
now, May I ask in what scenario IP_FORWARD is used?

Also I just did a quick search on LwIP + NAT, and I found this discussion: 
http://savannah.nongnu.org/task/?7506
Looks like someone was working on it but why NAT is not added to LwIP? Is it 
something not allowed to be done? I am confused as I see file attached to the 
posts are also missing.

Thanks again for clarifications.

Regards,
Ajay Bhargav