Re: [lwip-users] Sending to a non-local network without default netif set

[address@hidden]

HaaCee2 wrote:
> I am not entirely familiar with the ideas behind LwIP. But sourcebased
> routing is very much in line with rfc1122 (ip for hosts). I quote:
>
> > Under the Strong ES model, the route computation for an outgoing datagram
> > is the mapping:
> >
> >                           route(src IP addr, dest IP addr, TOS) -> gateway
> >
> > Here the source address is included as a parameter in order to select a
> > gateway that is directly reachable on the corresponding physical
> > interface. Note that this model logically requires that in general there
> > be at least one default gateway, and preferably multiple defaults, for
> > each IP source address.

Well, that excerpt is one of 2 possibilities in the RFC. The other 
possibility is to do like lwIP does. I admit though that it looks kind 
of strange sending packets with IP address A to the interface B just 
because you have a matching destination gateway on that netif...

By now, I'm tempted to add source-based routing as an option, although I 
expect people using lwIP wih more than one interface being only a small 
percentage...


Simon