[j-nsp] BGP/MPLS Question MX Platform

[Dean B]

Ok, that is going to show how inexperienced I am in MPLS/RSVP/etc. but what
is the SPT you are referring to and what JunOS config elements does it
correspond to?  Having trouble translating the terms into example config
:-)  I would probably just start with c (discard 100% of other traffic)
then perhaps look into the QoS.

Speaking of QoS, might another way to solve this (assuming I could mark
traffic eligible to discard) be to use use QoS on both sides of the
high-cost link and just discard that marked traffic?  Then I could just let
the existing ISIS/LDP stuff do it's thing.


On Wed, Aug 3, 2016 at 10:28 AM, Saku Ytti <saku at ytti.fi> wrote:

> On 3 August 2016 at 18:10, Dean B <jnprlist at gmail.com> wrote:
>
> Hey,
>
> > Thanks for everyone's suggestions.  RSVP-TE looks like it would be the
> > cleanest solution.  I'm still a little lost on how that would be
> > implemented.  Saku in what you are suggesting would the following be
> > correct:
> >
> > ISIS with traffic engineering enabled on all the ring links
> > RSVP enabled on all the ring links
> > LSPs with normal priority configured on each node to every other node for
> > BGP to use
> > LSPs configured for l2vpn use on each node that requires them and set
> them
> > to a high reservation priority
>
> I essentially have three options:
>
> a) use SPT, where the expensive link isn't used, put L2VPN with
> segment routing on the expensive link
> b) use SPT, where the expensive link isn't used, put L2VPN with RSVP
> on the expensive link
> c) use SPT, where the expensive link is used, have all traffic in RSVP
> tunnels, so that non L2VPN traffic will fall-off the SPT path, due to
> lack of capacity
>
> If the low-cost SPT breaks down, and only high-cost link is possible,
> what is your desired outcome?
>
> 1) blackhole 100% of traffic that would switch to the high-cost link
> 2) use QoS so that all existing traffic on high-cost link works, but
> also all other demand is moved there, and pushed through as much as
> possible
>
> For 2) all of a-c can do it.
> For 1) you need c
>
>
>
>
> >
> > So in case of a failure of one of the low-cost links the high reservation
> > priority on the l2vpn LSPs will only allow them to form on the expensive
> > path and the BGP LSPs will just be down?  What will keep BGP from just
> using
> > the IGP best path at that point?
>
>
>
>
> --
>   ++ytti
>