[j-nsp] BGP/MPLS Question MX Platform

[Dean B]

Thanks to Alexander, Saku, Mark and others...I have it working in the lab.
I created colored links with all being blue except the high cost path which
I made red.  I then only allow the l2circuit LSP onto the red path.  Then I
used forwarding table export policy to put the BGP traffic into the
appropriate LSP with strict mode:

policy-statement bgp-to-tunnel {
    term node-a {
        from community node-a;
        then {
            install-nexthop strict lsp LSP-B-A;
            accept;
        }
    }
    term node-c {
        from community node-c;
        then {
            install-nexthop strict lsp LSP-B-C;
            accept;
        }
    }
}

Now when the A-C link fails the l2circuit traffic switches over to the LSP
that is allowed on the red colored link and the BGP external transit routes
fall back to routing to reachable upstreams.  Now I just need to check on
what happens to customer prefixes inside our network.

It can't be this easy...so I must be missing something :-)

On Wed, Aug 3, 2016 at 4:40 PM, Alexander Arseniev <arseniev at btinternet.com>
wrote:

> Hello,
>
> On 03/08/2016 22:09, Dean B wrote:
>
>> 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.
>>
> There are several ways to do that.
> 1) use forwarding-table policy to associate BGP routes with a particular
> LSP
> https://www.juniper.net/documentation/en_US/junos15.1/topics
> /reference/configuration-statement/install-nexthop-
> edit-policy-options.html
> This policy should have 2 terms: term 1 from community BGP-ROUTE-COMM then
> install-nexthop lsp <name>; term 2 from community BGP-ROUTE-COMM then
> next-hop discard
> 2/ You can deny resolution of BGP routes' nexthop via inet.0, and let it
> only use inet.3.
> By default, BGP routes' nexthop is resolved via inet.3 and then, if no
> joy, via inet.0.
> If You deny inet.0 usage for BGP routes' nexthop resolution, BGP routes
> will be invaldated once LSP fails.
> The command is
> set routing-options resolution rib inet.0 resolution-rib inet.3
> 3/ You also can configure static discard routes in inet.3 table to set all
> BGP routes' nexthops to discard should A-C LSP fail:
> In router A: set routing-options rib inet.3 static route <router C
> loopback>/32 discard preference 8
> In router C: set routing-options rib inet.3 static route <router A
> loopback>/32 discard preference 8
> But - if there are MPLS VPN between A and C, and You want them continue
> using LDP, then (3) is not a good option.
> With (3), A-C MPLS VPN will stop working after A-C LSP fails whereas in
> option (2) only IP traffic will stop working.
>
>
> HTH
> Thx
> Alex
>