On 1/11/12 9:58 AM, Masataka Ohta wrote:
A better default could be that IGP will be automatically invoked if DHCP does not supply a default router.
That's ridiculous. You need some link state to even find a DHCP server. So, the very idea that DHCP would tell you where your routers are is preposterous on its face. Besides, that's terrible system design. You should never design a system where some code paths aren't exercised regularly.
If there are multiple IGPs are implemented, snooping IGPs' advertisement to know which is the locally available IGP may also be a good idea.
My point w.r.t. multiple next hop routers is that RA supplied information is not good enough, which means DHCP is no worse than RA even if there are multiple next hop routers.
I've not read the whole thread yet (I had read the start what seems to be weeks ago), but I'll pipe up here and point out that in my _original_ design, every host was running a link state IGP. Even without any router at all, you need link state to handle mobile nodes, hidden terminals, partitioned networks, satellite versus land-line unidirectional links, etc, etc, etc. Of course, all that was ripped out by the ignorant folks who came later. Thus, IPv6 is much worse at self-configuration, security, mobility, and *everything* than originally envisioned.