IPv6 Multi-homing (was IPv6 /64 links)

Tue Jun 26 02:22:33 UTC 2012

On Jun 25, 2012 6:38 PM, "William Herrin" <bill at herrin.us> wrote:
>
> On Mon, Jun 25, 2012 at 8:03 PM, William Herrin <bill at herrin.us> wrote:
> > Does SCTP operate on a list of IPv4 and IPv6 addresses received from
> > the application when it asks for a connect, parallelizing its attempt
> > to reach a live address? Or a DNS name which it resolves to find those
> > addresses? Or does it accept only one address at a time for the
> > initial connect, just like TCP?
>
> Hi Douglas,
>
> Another gentleman clarified for me privately: sctp_connectx() is
> listed as a new function in the 12/2011 standard. It accepts and uses
> multiple addresses during the initial connect.
>
> Good progress since the last time I looked at SCTP.
>
> I assume the SCTP API does not gracefully fall back to TCP for
> stream-oriented connections and UDP for datagram oriented connections,
> yes? So if an app author wants to use this in the real world as it
> exists in 2012, he'll have to juggle timeouts in order to try TCP if
> SCTP doesn't promptly establish. And he'll have to juggle the two APIs
> anywhere he does something more complex than send() and recv(). Yes?
>

There is some scope for this type of work.... This draft is expired, i
imagine it may come back soonish
http://tools.ietf.org/html/draft-wing-tsvwg-happy-eyeballs-sctp-02 now that
the ipv6 variant has shipped

SCTP is coming along, and it has a lot of promise.

CB

> Also, has there been improvement to the situation where an endpoint
> loses all of its IP addresses and wants to re-establish? Something
> like a notification to the app requesting a fresh list of addresses?
>
> Regards,
> Bill Herrin
>
>
> --
> William D. Herrin ................ herrin at dirtside.com  bill at herrin.us
> 3005 Crane Dr. ...................... Web: <http://bill.herrin.us/>
> Falls Church, VA 22042-3004
>