[j-nsp] BGP/MPLS Question MX Platform

Dean B jnprlist at gmail.com
Wed Aug 3 17:09:45 EDT 2016


Thanks.  I think the part I'm missing is associating the IP traffic to an
LSP and how to prevent it from just going back to IGP routing when the LSP
fails.  From everything I can see it will just drop back to IGP routes if
the LSP disappears.

On Wed, Aug 3, 2016 at 4:03 PM, Saku Ytti <saku at ytti.fi> wrote:

> Without reading or doing the work (yay for drive-by-support). Be sure
> you forbid the paths from going into secondary paths, just allow them
> to fail.
>
>
> Also look into affinities/colors,  you can colour code links, and then
> tell LSP which colors it is allowed to traverse. Make all your links
> blue, but the high-cost link red, and make sure IP traffic LSPs are
> allowed to use only blue, but L2VPN is also allowed to use red.
>
> Sorry for not providing more specific, or configs. I'm lazy, but I
> also see that you have good grasp in what you're doing, so I'm
> confident you'll be able to get this working.
>
>
> On 3 August 2016 at 23:38, Dean B <jnprlist at gmail.com> wrote:
> > Ok, I have attempted to lab this up...config here
> > http://pastebin.com/53Ebsd7X
> >
> > I must still be missing something...BGP appears to still use the IGP and
> go
> > across the high-cost link when I disable the low-cost link between B-C:
> >
> > (on B)
> > 2.2.2.0/24         *[BGP/170] 00:12:13, localpref 100, from 10.10.10.1
> >                       AS path: 174 I, validation-state: unverified
> >                     > to 10.0.1.1 via lt-0/0/10.2, label-switched-path
> > LSP-B-C-L2VPN
> >
> > The other LSPs do drop that should not be going over the high-cost link.
> > I'm guessing I need some knob to tell BGP which LSP to use or not to use?
> >
> > dean at lab# run show rsvp session logical-system A
> > Ingress RSVP: 1 sessions
> > To              From            State   Rt Style Labelin Labelout LSPname
> > 10.10.10.2      10.10.10.3      Up       0  1 FF       -        3 LSP-A-B
> > Total 1 displayed, Up 1, Down 0
> >
> > Egress RSVP: 1 sessions
> > To              From            State   Rt Style Labelin Labelout LSPname
> > 10.10.10.3      10.10.10.2      Up       0  1 FF       3        - LSP-B-A
> > Total 1 displayed, Up 1, Down 0
> >
> > Transit RSVP: 2 sessions
> > To              From            State   Rt Style Labelin Labelout LSPname
> > 10.10.10.1      10.10.10.2      Up       0  1 FF  299792        3
> > LSP-B-C-L2VPN
> > 10.10.10.2      10.10.10.1      Up       0  1 FF  299808        3
> > LSP-C-B-L2VPN
> > Total 2 displayed, Up 2, Down 0
> >
> > dean at lab# run show rsvp session logical-system B
> > Ingress RSVP: 2 sessions
> > To              From            State   Rt Style Labelin Labelout LSPname
> > 10.10.10.1      10.10.10.2      Up       0  1 FF       -   299792
> > LSP-B-C-L2VPN
> > 10.10.10.3      10.10.10.2      Up       0  1 FF       -        3 LSP-B-A
> > Total 2 displayed, Up 2, Down 0
> >
> > Egress RSVP: 2 sessions
> > To              From            State   Rt Style Labelin Labelout LSPname
> > 10.10.10.2      10.10.10.3      Up       0  1 FF       3        - LSP-A-B
> > 10.10.10.2      10.10.10.1      Up       0  1 FF       3        -
> > LSP-C-B-L2VPN
> > Total 2 displayed, Up 2, Down 0
> >
> > Transit RSVP: 0 sessions
> > Total 0 displayed, Up 0, Down 0
> >
> > dean at lab# run show rsvp session logical-system C
> > Ingress RSVP: 1 sessions
> > To              From            State   Rt Style Labelin Labelout LSPname
> > 10.10.10.2      10.10.10.1      Up       0  1 FF       -   299808
> > LSP-C-B-L2VPN
> > Total 1 displayed, Up 1, Down 0
> >
> > Egress RSVP: 1 sessions
> > To              From            State   Rt Style Labelin Labelout LSPname
> > 10.10.10.1      10.10.10.2      Up       0  1 FF       3        -
> > LSP-B-C-L2VPN
> > Total 1 displayed, Up 1, Down 0
> >
> > Transit RSVP: 0 sessions
> > Total 0 displayed, Up 0, Down 0
> >
> > On Wed, Aug 3, 2016 at 12:18 PM, Saku Ytti <saku at ytti.fi> wrote:
> >>
> >> On 3 August 2016 at 19:36, Dean B <jnprlist at gmail.com> wrote:
> >>
> >> Hey,
> >>
> >> > Hey Saku thanks for clarifying...it makes sense now.  So for your
> option
> >> > "c"
> >> > I would just set the ISIS metric to have a higher cost on the
> expensive
> >> > A-C
> >> > link so that it would not normally be used right?  I have sample lab
> >> > logical
> >> > system config here: http://pastebin.com/uzHtzWrw
> >>
> >> No. In option C you'd have proper metric, metric which cases expensive
> >> link to be used normally. But as all traffic would be in RSVP tunnels,
> >> you'd ultimately be unable to put LSPs on the SPT path, because there
> >> isn't enough capacity, then subsequent LSPs would fall back to off SPT
> >> paths, to avoid the congested link.
> >> And if there are no available path, then some LPSs would just simply
> >> not establish and you'd blackhole traffic.
> >>
> >> > I'm assuming I need to add an additional LSP to each node that has a
> >> > higher
> >> > priority and then use that LSP for the l2circuit traffic.  What else
> >> > would I
> >> > need to get the option "c" with blackhole of other traffic during
> >> > low-cost
> >> > path failure?
> >>
> >> For C you'd need need full-mesh RSVP.
> >>
> >> --
> >>   ++ytti
> >
> >
>
>
>
> --
>   ++ytti
>


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