[rbridge] Max Network size

[Alper Yegin]

> only when you don't have config info. If you move ethernets within an
> enterprise (i.e., within a campus deployment), you don't necessarily
> contact DHCP when you move.

Even than the host needs to perform some tests to know it is still
connected to the same IP subnet. Like the reachability test outlined in
http://ietf.org/internet-drafts/draft-ietf-dhc-dna-ipv4-11.txt . The
test is using ARP....

 
> Sure. But this is, in a lot of ways, just another version of an
> optimization. We definitely need to cover the case where the
> optimization isn't in place anyway...

I agree.....

Let's not rely on presence of optimizations. Nevertheless let's
enumerate them, so that people don't think they are always stuck with
the worst case scenario.

Alper