Re: Why specify a default router?

[The Orange Rider <theorangerider@gmail.com>]

Paul TBBle Hampson wrote:
> > There're also "non-broadcast multiple access" link layers where router
> > solicitation might be tricky; I'm not familiar with the details.  I think
> > 6to4 is one such; the IPv4 Internet can be treated as your link layer, but
> > you can't send a packet to all IPv4 nodes looking for a router.
> 
> Actually, IPv4 Anycast is supposed to do something like that, except with
> routing trickery. You send to 192.88.99.1, and IP is supposed to drive your
> packets to the nearest node that is advertising that address. It's kinda like

I just skimmed my O'Reilly book on IPv6 Essentials and (unless I
skimmed it wrong) it looks like yes you can either manually configure
a default gateway to use as a 6to4 relay, or you can send it to a IPv4
router anycast address and it'll be taken care of. Both ways should
work. I think RFC 3056 specifies 6to4 with a manual setting and RFC
3068 defines the anycast address that can be used.

> the ::ff02 (is that right?) routers-on-link IPv6 multicast link you use to
> solicit routers.

I'm pretty sure it's ff02::2, but that's because I have a book here in
front of me =)

> I doubt 6to4 does broadcast router solicition, but I expect it does something
> similar to directed neighbour discovery when given a new link-local destination
> address (eg another 6to4 address).

I should probably read up more on 6to4, but everything seems clear so far.

I believe that answers my question. Thanks for the help guys!

Orange