Re: [homenet] sorting out the right ipv6 addr to choose and name in a source specific world

Michael Richardson <mcr+ietf@sandelman.ca> Thu, 18 December 2014 15:08 UTC

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From: Michael Richardson <mcr+ietf@sandelman.ca>
To: Dave Taht <dave.taht@gmail.com>
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Date: Thu, 18 Dec 2014 10:07:59 -0500
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Cc: dnsmasq-discuss <dnsmasq-discuss@lists.thekelleys.org.uk>, HOMENET <homenet@ietf.org>, "babel-users@lists.alioth.debian.org" <babel-users@lists.alioth.debian.org>
Subject: Re: [homenet] sorting out the right ipv6 addr to choose and name in a source specific world
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Dave,
my take is that applications, and the entire gai.conf/getaddrinfo() library
is broken.  Applications can neither be updated nor be trusted to know enough
about the system to be able to make a proper decision.

Somewhere, someone was working on a new connect(2) call that took FQDNs
rather than sockaddr's, such that the kernel could take ownership of this
problem. (Of course, actually solving the problem in a kernel is probably the
wrong answer).
What is necessary is some new infrastructure inside the box which becomes
standardized (like sockets API was), with some daemon that thinks about the
best source addresses is, and possibly gets involved with routing protocols.
(I'm told that OSX has a sophisticated state machine that combines DHCP and
1x, and wifi... it sounds like it could be the start of such a thing)

I think that shim6 and mptcp are answers in this equation.

shim6 has, I'm told, deployment issues which make me very very sad.
mptcp, I'm told, is likely to show up in Apple and Google products and
infrastructure, and my idea (and many others) is that you don't always have
to pick the perfect address for the SYN, just one that works, but rather one
can add better addresses as one discovers them.

--
Michael Richardson <mcr+IETF@sandelman.ca>, Sandelman Software Works
 -= IPv6 IoT consulting =-