IPv6 Multi-homing (was IPv6 /64 links)

Tue Jun 26 01:37:54 UTC 2012

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?

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/>
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