Re: RFC6724-bis?

[Michael Richardson <[e-mail]>]

David Farmer <farmer=[e-mail]> wrote:
    > Experience has shown us that despite recommendations to the contrary, ULAs
    > are in the Public DNS, how much is questionable, but it exists
    > nonetheless.

... I think it's a feature of IPv6 over IPv4 :-)

    > Now I have some related questions, is this connection failure going to
    > result in a full TCP timeout or happy eyeballs timer expiring? Or, will an
    > ICMP destination unreachable or other ICMP message shortcut the TCP timeout
    > or the happy eyeballs timer? Will most CPEs on the market generate an

I think that we should be getting ICMPs.
That's also why I think that we should have 2000::/3 routes, rather than
default routes.

    > destination unreachable, an ICMP administratively disallowed, or simply
    > just forward the packet to the upstream ISP using the default route? Would
    > most ISPs generate an ICMP destination unreachable for the ULA in this
    > case? Finally, even if the ISP’s router generates the ICMP destination
    > unreachable, in most cases, I don’t believe the ISP will have a route back
    > to the originating ULA address anyway.

    > So, I think we are probably better off with SA/DA selection not preferring
    > ULA unless the prefix is know to be local.  This is the best guess.

I totally agree.
I thought that we were just debating about the different ways that we would
recommend implementing this.  That presence of a /64 ULA implied that the
entire /48 is probably routable.  That maybe we need some additional signal
if there were multiple ULAs present.



--
Michael Richardson <[e-mail]>, Sandelman Software Works
 -= IPv6 IoT consulting =-