RE: v6 & DSL / Cable modems

["TJ" <trejrco () gmail com>]

> > > I suppose you can individually configure every host to get itself
> > > temporary addresses from RA announcements.  This isn't usually a
> > > good default configuration, but OS implementation already seems to
> > > be inconsistent on the default configuration here.  So we're back to
> > > the IPv4 dark ages where you have to walk around to all the devices
> > > to effect changes in policy (beyond prefix field contents).
> >
> >
> > I'm not sure, but you seem to be implying that you need to configure
> > hosts to tell them to use RA or DHCPv6 to get addresses. My apologies
> > if this is not your intention.
> >
> > RA messages are always going to be sent by routers and received by
> > hosts, even if DHCPv6 is being used for address assignment.
>
> This does not seem to be generally true:
>
> - For the routers I am most familiar with (Juniper M/MX), you need to
> explicitly turn on router advertisement to make the router perform this.
> I.e. it is perfectly possible to have an interface with an IPv6 address
> which does *not* send RAs.

Yes, vendors differ ... for Ciso/IOS - broadcast capable, multi-access
interfaces (a la Ethernet) will automatically send RAs ones a /64 IPv6
address is configured.  Or once you explicitly tell it to advertise one.


> - For the operating system I am most familiar with (FreeBSD), RAs are
> *not* accepted by default if the interface in question is configured with a
> static IPv6 address.

I don't believe that is the general behavior, and specifically - for Win* a
static being configured does not prevent autoconfiguration.
And this is the correct behavior - to allow for cases where multiple
prefixes are correct/expected, and only one is static.


> Both of these choices seem perfectly reasonable to me.

I slightly disagree on the latter; autoconfiguration in the presence of RAs
(including a (or several) prefix options) should be the default.



((... and now begins (continues, really) the pseudo-religious debate between
the autoconfiguration people and the DHCPv6 people ...))
/TJ