Segment Routing

Tue May 22 20:40:40 UTC 2018

On Tue, May 22, 2018 at 9:59 AM Saku Ytti <saku at ytti.fi> wrote:

> On 22 May 2018 at 17:43, steve ulrich <sulrich at botwerks.org> wrote:
>
> Hey,
>
> > sorry, yes. i was referring to SRTE wrt the pop operation.
>
> Yup RSVP=>SR is more ambiguous and debatable than LDP=>SR which is
> unambiguous win.
>
> > not labels but they are encoded as labels.  i hope operators have the
> option
> > to configure common/consistent label ranges, but i don't necessarily
> assume
> > it.  tooling to resolve this will be required just as in the LDP world.
>
> I've not had this tooling in LDP world, and not anticipating to need
> it in SR world. But maybe I'm missing something, what kind of
> information do you need in LDP world which you need to develop tooling
> for, and how does the problem+solution translate to SR world?
>

in the day's of yore, i know a few folks who built tooling to validate
and/or detect failure to sync between the IGP and LDP or detect data plane
black holing behaviors caused by resolution in the RIB w/no complementary
label allocation (or LDP convergence lagging significantly).
implementations have come a long way since then.  but yeah, IGP-LDP sync
lag has been a thing for some folks.

in a world of anycast/prefix-SIDs some of this doesn't necessarily go away,
it just looks kind of different.  though to be fair, this alignment
improves (the IGP/LDP convergence sync case goes away) for all the reasons
you've cited previously in this thread.

-- 
steve ulrich (sulrich at botwerks.*)