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

[Ted Lemon <[e-mail]>]

On Jun 1, 2014, at 9:59 PM, joel jaeggli <[e-mail]> wrote:
> Ted I think you need rethink what you're claiming. for one rfc 6555
> makes no claims about ipv6 address selection between multiple addresses.
> it in fact sets aside the issue of having more than the two address
> familes to chose from. I daresay if you have six v6 routes you probably
> don't want to make six requests and see which one is fastest as a
> general rule.

How is this different than doing happy eyeballs between v4 and v6?   Is it different because you're sextuply multi-homed?   I agree that that begins to look a bit problematic, but the more usual two-provider case is pretty much the same as regular happy eyeballs.

> you'remore likely to do ecmp if you simply treat all
> nexthops as though they were equivalent, which you might not want to do
> if they aren't (backup via LTE is probably not something you want to
> exercise all the time even if it's equivlant speed to your cable
> connection because it's more costly and has a datacap).

Right, that's a problem.

> source address selection based on nexthop is pretty straight forward.
> most unixes can do that. invalidating a nexthop when the route should no
> longer be used is propertly the domain of routing.  This is not even a
> benifit of ipv6 in the sense that it can work in ipv4 as anyone with an
> appropriately configured router  can attest (it's what the multihomed
> nat box actually does after all).

I've never operated one of these, but I'll take your word for it.   The fact that it works with IPv4 and NAT isn't very interesting to me.

Correct me if I am wrong, but what you have written appears to be a more detailed way of saying "happy eyeballs for multihoming won't happen, in my opinion, and multihoming for connection originators probably won't happen either, at least without NAT."   If so, that's a fine opinion to have, and may even be correct, but it's not an opinion I am willing to just accept without trying to do better (according to my opinion as to what's "better").