Routing

Hi members,

I need to do traffic engineering in backbone IP/MPLS from point A to point B, but just need some prefixes, part of the traffic is sent via TE and I'm seeing all traffic exiting via TE from point A to B.

I know the next-hop for both routes is the same. So, the router will prefer the next-hop in inet.3. What do I need to send only the prefix 10.152.42.0/25 via TE and not all traffic?

Summary:
Point B:10.251.255.74
Prefix must use the TE: 10.152.42.0/25
Name's VPN traffic: pb-dados
Another prefix you should not use the TE: 10.152.61.128/26

Configuration used in point A:

>protocols mpls

label-switched-path TIVIT_to_DIVEO {

    to 10.251.255.74;

    install 10.152.42.0/25 active;

    no-cspf;

    optimize-timer 1;

    primary TIVIT_to_DIVEO_Replica;

}

path TIVIT_to_DIVEO_Replica {

    10.251.0.122 strict;

}

interface lo0.0;

interface ge-3/0/2.0;

interface fxp0.0 {

    disable;

}

interface ae0.0;

interface xe-0/0/0.0;

>protocols rsvp

interface fxp0.0 {

    disable;

}

interface ge-3/0/2.0;

Expected behavior:

>show route 10.152.42.0

inet.0: 319 destinations, 319 routes (318 active, 0 holddown, 1 hidden)

+ = Active Route, - = Last Active, * = Both

10.152.42.0/25     *[RSVP/7] 20:35:39, metric 22

                    > to 10.251.0.122 via ge-3/0/2.0, label-switched-path TIVIT_to_DIVEO

pb-dados.inet.0: 9783 destinations, 21974 routes (9783 active, 0 holddown, 0 hidden)

+ = Active Route, - = Last Active, * = Both

10.152.42.0/25     *[BGP/170] 20:35:39, MED 0, localpref 110, from 10.251.255.1

                      AS path: 65100 ?

                    > to 10.251.0.122 via ge-3/0/2.0, label-switched-path TIVIT_to_DIVEO

                    [BGP/170] 20:35:39, MED 0, localpref 110, from 10.251.255.2

>traceroute 10.152.42.126 routing-instance pb-dados

traceroute to 10.152.42.126 (10.152.42.126), 30 hops max, 40 byte packets

 1  10.251.0.122 (10.251.0.122)  27.720 ms  27.543 ms  27.621 ms

     MPLS Label=799192 CoS=0 TTL=1 S=1

 2  10.251.40.66 (10.251.40.66)  28.318 ms *  27.481 ms

Unexpected behavior::

>show route 10.152.61.189

pb-dados.inet.0: 9784 destinations, 21974 routes (9780 active, 4 holddown, 0 hidden)

+ = Active Route, - = Last Active, * = Both

10.152.61.128/26   *[BGP/170] 20:59:26, MED 0, localpref 110, from 10.251.255.1

                      AS path: 65100 ?

                    > to 10.251.0.122 via ge-3/0/2.0, label-switched-path TIVIT_to_DIVEO

>traceroute 10.152.61.189 routing-instance pb-dados

traceroute to 10.152.61.189 (10.152.61.189), 30 hops max, 40 byte packets

 1  10.251.0.122 (10.251.0.122)  27.630 ms  27.527 ms  27.468 ms

     MPLS Label=799192 CoS=0 TTL=1 S=1

 2  10.251.40.66 (10.251.40.66)  27.522 ms *  27.837 ms

hi

I can think of two ways to do this:

1. create a secondary loopback on each end of this LSP and install the secondary loopback in the LSP.

make a route change for your 10.152.42.0 prefix to the next-hop = secondary loopback.

label-switched-path path1 {
    no-install-to-address;
    to <primary-loopback>;
    install <secondary-loopback>
}

 or a variation on this.

2.

you may need to use the Junos equivilent of Policy Based Routing called Filter Based Forwarding.

there is an example of this prefix to lsp mapping in the free JNCIE-M PDF page: 185

to summarise:

[edit policy-options policy-statement lsp-map]
lab@r7# show
term 1 {
from {
route-filter 10.152.42.0/25 exact
}
then {
install-nexthop lsp TE-LSP;
accept;
}
}
term 2 {
then {
install-nexthop lsp <other-lsp>;
accept;
}
}

then you need to export the policy to the forwarding engine:

[edit routing-options]
lab@r7# set forwarding-table export lsp-map

read that section as its a very powerful feature.

Hi William, thank you very much

Gabriel Farias

gfarias@qos.com.br