Misconceptions, was: IPv6 RA vs DHCPv6 - The chosen one?

Wed Dec 28 12:21:44 UTC 2011

Iljitsch van Beijnum wrote:

> Just to clear up a few misconceptions:

Only to add yet another misconception without any clearing up?

> Router advertisements are exactly what the name suggests,
> routers advertising their presence.
> The first function of router advertisements is to tell
> hosts where the routers are,

OK, so far.

> so the hosts can install a default route.

WRONG.

Routers are not "a default route".

If a host receives RAs only from a router, the host can do
nothing other than installing the router as the default
router. If not, however, the host must directly be involved
in IGP activities, or, the following end to end argument
is applicable:

	The function in question can completely and correctly
	be implemented only with the knowledge and help of
	the application standing at the end points of the
	communication system. Therefore, providing that
	questioned function as a feature of the communication
	system itself is not possible.

						Masataka Ohta

PS

Granted that the notion of default router of IPv4 is no better
than that of IPv6.