Re: [lwip-users] Communication between different subnets

[Kieran Mansley]

On Tue, 2010-09-14 at 02:04 -0700, hellish wrote:
>  * For unicast addresses, the packet is submitted to etharp_query().
> In
>  * case the IP address is outside the local network, the IP address of
>  * the gateway is used.
>    So lwip modified destination IP address of the packets(sent from my
> board) to that of the gateway?  This confused me. Why change the
> destination
> IP address? According to my network textbook, it is the destination
> MAC
> address that should be changed to that of the gateway.

Yes, your textbook is right.  But to find the MAC address of the gateway
we have to use the IP address of the gateway in the lookup.  The packet
itself will still be sent with the IP address of the FTP server.

It should just work if you've configured the netif with the gateway
address properly.

Can you get a packet capture to show what's going wrong.  You've said it
doesn't work but we need more information about what goes wrong to debug
this problem.

Kieran