Re: [Dcrouting] draft-przygienda-rift-03

[Tony Przygienda <[e-mail]>]

On Sat, Jan 13, 2018 at 11:21 AM, Robert Raszuk <[e-mail]> wrote:

> Hi Tony,
>
> > ​
> if you're willing to provision things correctly yourself via S-PGP.
>
> I am not willing to do that. I would like routing to do it for me
> auto-magically.
>

The price of that would be that you can run strict SPF only then and loose
all the non-equal cost forwarding, including true anycast. Plus, once you
think that through in general sense you basically end up with host
addresses everywhere (since if you use aggregates you'll blackhole on link
failures). If you want to avoid SPF and host routes while still asking for
all the things you ask, then as a very experienced and highly regarded
architect here puts it to end such discussions "your problem is overly
constrained" and there is no protocol/algebra whatsoever that will give you
that ...


> But yes you got the question right. I was asking for shortcuts between
> last levels of fabric. Not so much between Node 111 & Node 112 - but you
> said it is optional so ok.
>
> Side note: PGP abbrev. for vast majority of people means completely
> different thing then what you defined it to mean locally in your draft. I
> highly recommended you rename it in -05 version to PGD (policy guided
> destination(s) or PGR (policy guided reachability/routing).
>

Sigh, I warned when the acronym was picked.  Come up with something that is
a word, the funnier the better, easier to remember for our brains that way.
Can be 4 letters ;-)  and will get you an Ack mention l;-)


>
> Now requirement to switch off miscabling detection is not acceptable. You
> are stating that only rift knows how should I cable my fabric ?
>

No, it doesn't. You asked in your previous email for "red lights" when
topology is built incorrectly and you have it. Now you don't want it. Both
states cannot be true @ the same time unless you are entangled ;-)

> Node112 can actually even go haywire
>
> That may be not best property of a routing protocol :)
>
>
"haywire" is the wrong word. Rather,  I should have said "it will even
allow that". Now, why would you want the same src/dst pair sometimes
shortcut on the horizontal link and sometimes go up to spine I can't
imagine but you ask for all kind of very non-obvious things you seem to
like so I'm just pointing the space of possibilities out to you ...


-- tony