Riverstone Networks WICT1-12 User Manual

Riverstone Networks RS Switch Router User Guide Release 8.0 17-105

MPLS Configuration

Traffic Engineering

Constrained Path Selection Configuration Example for OSPF Traffic Engineering

The following example illustrates constrained path selection based on an administrative group with OSPF as the IGP.
The same administrative group must be configured on all routers in the LSP. In the example shown in

Figure 17-22

the administrative group ‘SKY’ with a value of 7 is created on all LSRs and applied to the following interfaces: R1R2b
on R1, R2R1b and R2R3 on R2, and R3R2 on R3. An LSP ‘LSP1’ is configured on R1 with R3 as the LSP destination
and SKY as the administrative group. That means that even though there are two possible paths from R1 to R3, CSPF
selects the path that traverses through the interfaces where the administrative group SKY is applied.

Timesaver

Click on the router name (in blue) to see the corresponding configuration.

Figure 17-22 Constrained path selection by administrative group

The following is the configuration for R1:

! Create interfaces

interface create ip R1R2 address-netmask 16.128.11.10/24 port gi.4.1

interface create ip R1R2b address-netmask 94.9.9.10/24 port gi.3.1

interface add ip lo0 address-netmask 1.1.1.1/16

! Configure OSPF

ip-router global set router-id 1.1.1.1

ospf create area backbone

ospf add stub-host 1.1.1.1 to-area backbone cost 10

ospf add interface R1R2 to-area backbone

ospf add interface R1R2b to-area backbone

ospf set traffic-engineering on

Enable traffic engineering extensions for OSPF

ospf start

! Create and apply admin-group

mpls create admin-group sky group-value 7

mpls add interface R1R2b

mpls set interface R1R2b admin-group sky

R1R2

R1R2b*

R2R1

R2R1b*

R2R3*

R3R2*

Interface where administrative group is applied

CSPF-selected Path

R1R2b*