Hi Peter,

Take SR-MPLS and RFC8667.

Take RFC7810

Take RFC5120

literally anything which uses inter-area leaking today.

Thx,
R.




On Mon, Jan 3, 2022 at 6:18 PM Peter Psenak <[email protected]> wrote:

> Robert,
>
> On 03/01/2022 18:04, Robert Raszuk wrote:
> > Peter,
> >
> >  > We want network to be summarized all times
> >
> > Please - can you answer my question which was already stated at least
> > twice ?
> >
> > How can you summarize PE addresses if outside of reachability they
> > advertise and leak across areas lots of other important information in
> > an opaque to the IGP meaning ?
>
> like what?
>
> thanks,
> Peter
>
>
> >
> > What other transport those opaque gen-art /gen-app  information will
> > take once you summarize the reachability and stop inter-area leaking ?
> >
> > Many thx,
> > R.
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > On Mon, Jan 3, 2022 at 5:56 PM Peter Psenak <[email protected]
> > <mailto:[email protected]>> wrote:
> >
> >     Chris,
> >
> >     On 03/01/2022 17:18, Christian Hopps wrote:
> >      >
> >      > Peter Psenak <[email protected] <mailto:[email protected]>>
> writes:
> >      >
> >      >> On 03/01/2022 16:21, Christian Hopps wrote:
> >      >>>
> >      >>>> On Nov 29, 2021, at 7:39 PM, Les Ginsberg (ginsberg)
> >     <[email protected]
> >     <mailto:[email protected]>> wrote:
> >      >>>>
> >      >>>> Tony –
> >      >>>>    Let me try one example – see if it helps.
> >      >>>>    Summarization is used in the network.
> >      >>>> But customer identifies a modest number of key nodes where it
> >     wants to detect loss of reachability ASAP. Unfortunately, customer
> >     is unable to assign addresses which are outside of the summary to
> >     these nodes.
> >      >>>
> >      >>> I think this does in fact capture the problem trying to be
> >     solved here, nicely.
> >      >>
> >      >> not really.
> >      >> In fact assigning addresses to the nodes in a way that they are
> >     part of the
> >      >> summary is the right thing to do.
> >      >
> >      > No, not if you want more detailed information about specific
> >     reachability it's not. And ....
> >
> >
> >     typically you want to summarize all prefixes inside the area when
> >     advertising outside the area. And you want to know about some of
> these
> >     prefixes when they are lost to help convergence.
> >
> >
> >      >
> >      >> The problem we are trying to solve is to use the summarization
> >     but without the
> >      >> loss of the fast notification of the node down event.
> >      >
> >      > You want more specific information about reachability, but you
> >     just want to do it when the network is stressed and undergoing
> change.
> >      >
> >      > So the "works now" way of not summarizing these important
> >     prefixes has the state in the network when it's working, so you know
> >     adding and removing it is something the network is already capable
> >     of handling.
> >      >
> >      > New signaling that *only* is created when things start failing,
> >     tests the infrastructure at exactly the wrong time.
> >
> >     In 99,99% of cases there will be only single pulse generated when
> >     one PE
> >     goes down. That itself is a very rare event itself.
> >
> >     We can easily limit the number of pulses generated on ABR to a single
> >     digit number to cover the unlikely case of many PEs in area becoming
> >     unreachable at the same time.
> >
> >
> >      >
> >      > If a failing network can handle the extra state, then a
> >     functioning stable network of course can too.
> >
> >     no, that's not what we claim. We want network to be summarized all
> >     times
> >     and generate limited number of pulses at any given time to help the
> >     network converge fast in case where single (or very few) PEs in an
> area
> >     go down.
> >
> >     thanks,
> >     Peter
> >
> >
> >
> >      >
> >      > Thanks,
> >      > Chris.
> >      >
> >      >>
> >      >> thanks,
> >      >> Peter
> >      >>
> >      >>
> >      >>> One solution very simple solution that works today is:
> >      >>> - Tell the customer they can't do this, but they *can* modify
> >     their addressing
> >      >>> (this is literally what they do for a living) so that they
> >     don't have this
> >      >>> problem.
> >      >>> Do we *really* want modify our IGPs (a BIG ask) with some
> >     pretty questionable
> >      >>> changes, just to save the operators the trouble of doing their
> >     job correctly?
> >      >>> Maybe the answer here is this isn't a good idea, and we should
> >     move on...
> >      >>> Thanks,
> >      >>> Chris.
> >      >>> [as wg member]
> >      >>> _______________________________________________
> >      >>> Lsr mailing list
> >      >>> [email protected] <mailto:[email protected]>
> >      >>> https://www.ietf.org/mailman/listinfo/lsr
> >     <https://www.ietf.org/mailman/listinfo/lsr>
> >      >>>
> >      >
> >      >
> >
>
>
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