Re: [v6ops] PI [ULA draft revision #2 Regarding isolated networks]

[Gert Doering <[e-mail]>]

Hi,

On Sun, Jun 01, 2014 at 07:28:12PM -0700, joel jaeggli wrote:
> So don't asssume that every application needs to be aware of and test
> for which path is working, not only is that needless complexity pushed
> up into the stack. let your routers do their job and cease routing when
> their upstream connectivity is lacking.

Well.  It might not have been your intention, but what you said is very
clear "we're not going to make multihoming in the homenet case work".

In the case

    host --> router --> ISP A ---->  ISP C --------+
	       +------> ISP B ---->  ISP D ------> ISP E --> target

where "host" has source addresses A and B, and there is a problem at 
ISP *C*, preventing connectivity via A->C->, how exactly is the homenet
router "router" supposed to *know* that, or even solve it?

Assuming "as long as connectivity to ISP A is there, the whole Internet
will be reachable via ISP A" is completely ignoring reality.  Blackhole
issues happen (where even BGP to the customer router won't help you)...


OTOH, proper source address failover on "host" to source address B would
very nicely solve this whole category of connectivity issues - and (by
enforcing halfway symmetric return traffic via ISP B) would actually solve
it *better* than BGP routing, which might need manual fiddling with the
router to remove "ISP C" from the path.

(IETF is complaining about lack of operator input.  Here is operator input.
Don't ignore it, otherwise operators get bored and find solutions outside
IETF space, like, with NAT)

Gert Doering
        -- NetMaster
-- 
have you enabled IPv6 on something today...?

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