[lwip-users] VRF with LwIP

[Antoine Zen-Ruffinen]

Hi list,

I need your expertise. I am developing a device that will have two Ethernet 
interface using LwIP 2.0.1. The aim of having two interface on this device is 
to have the device connected into two physicaly separated LANs, let's say 
"management" LAN and "customer" LAN. I am worried about the case when both 
interface get the same private IP address (like 192.168.1.xxx) but in 
physically separated networks (I think that could happened).

 I know that that is possible under GNU/Linux using so called "Virtual Routing 
and Forwarding (VRF)"  (see 
https://www.kernel.org/doc/Documentation/networking/vrf.txt). Is LwIP able to 
handle this? It means remember from which interface a TCP connection was 
initiated  or to bind socket to a "netif" object and not only to an IP and then 
to forward outgoing packets to the right interface. It will also need to have 
two routing and ARP table I think.

Also, I think a possible solution would be to have TWO stack running in 
parallel (I know, it would consume twice the RAM). Has anybody ever done this ? 
Does the code allow this, or is the TCP/IP stack "singleton" ?

Thanks for your reply!

Antoine