mesh portal discovery

[John Watlington]

> I completely fail to see why we need the DHCP server to get the IP  
> address
> of the nearest MPP or get the optimal path to and from it.

The MPP discovery mechanism originally proposed worked great for getting
packets out of the mesh through the shortest path.   The problem was  
that
outside of running NAT on each MPP, there wasn't a good way to ensure
that packets sent to that laptop entered the mesh through the same MPP.

That is currently handled (in IPv4) by using a different DHCP range  
for each
MPP, and routing to the appropriate MPP based on those ranges.

> As for the multiple radio scenario at the schools, you can address  
> that
> with two different ways: bridging  between the interfaces on the  
> server or
> -if you want something quicker-, use a different autoIP range for each
> channel.


We briefly discussed using a different autoIP range, and decided it was
difficult to implement.

wad