Cisco Crosswork Network Controller 7.2 Traffic Engineering and Optimization

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Cisco Crosswork Network Controller 7.2 Traffic Engineering and Optimization

Sample policy and device configurations

Updated: August 4, 2025

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Provides practical examples for configuring devices to ensure successful operation of traffic engineering and telemetry functions. It outlines the necessary steps for creating policies and mapping link attributes, enabling administrators to effectively manage and visualize network services within the controller environment.

This section provides samples of policy and device configurations related to Traffic Engineering and Optimization functions.

To ensure that Traffic Engineering and telemetry functions operate successfully within Crosswork Network Controller, you must properly configure the devices. For more details about device configuration for other Crosswork Network Controller functions, refer to the "Onboard Devices" chapter in the Cisco Crosswork Network Controller 7.2 Administration guide.

PCC-initiated SR-TE policy example

This example demonstrates the configuration of an SR-TE policy on the headend router. The policy uses a dynamic path that is computed by the headend router based on specified affinity constraints. In this example, a policy named SampleSRTE is created with the following attributes: a color value of 100, a candidate preference of 100, a metric of type TE, and an affinity constraint to exclude links assigned the color red.

Refer to the SR configuration documentation for your specific device to view descriptions and supported configuration commands (for example, Segment Routing Configuration Guide for Cisco ASR 9000 Series Routers).

segment-routing
  traffic-eng
    policy sampleSRTE
      color 100 end-point ipv4 1.1.1.2
      candidate-paths
        preference 100
          dynamic
            metric
              type te
            !
          !
          constraints
            affinity
              exclude-any
                name RED
              !
            !
           !
         !
       !

Policy source-address configuration to support multiple loopback IP addresses

In order to support multiple loopback IP addresses, these policy configurations must be included on any PCC device that will act as the headend or origination point for a policy.

Global configuration for all policies 

Router# segment-routing traffic-eng candidate-paths all source-address ipv4 ip-address

Configuration for a specific policy 

Router# segment-routing traffic-eng policy policy-name source-address ipv4 ip-address

PCC-initiated RSVP-TE tunnel example

Affinity map configurations

Affinity maps allow network operators to associate human-readable names (such as "red," "low delay," or "high bandwidth") with specific bit positions that represent link attributes. If an affinity mapping is not defined in the Crosswork Network Controller UI, the affinity name is displayed as "UNKNOWN". To configure the affinity attribute for visualization purposes as part of an SR-TE policy, Tree-SID, RSVP-TE tunnel, or any other policy supported by Crosswork Network Controller, the affinity map configured on the device must also be recreated in Crosswork Network Controller. Start by collecting the affinity mappings configured on the device, and then define the same mappings in the Crosswork Network Controller UI with matching names and bit positions.

SR-TE affinity map configuration on a device

This example is a sample SR-TE affinity mapping configuration on a device. For more information, see Configure TE link affinities.

RP/0/RP0/CPU0:c12#sh running-config segment-routing traffic-eng affinity-map
   segment-routing
    traffic-eng
      affinity-map
        name red bit-position 1
        name blue bit-position 5
        name green bit-position 4
      !
    !
  !

Flexible algorithm affinity map configuration on a device

This example is a sample flexible algorithm affinity mapping configuration on a device. For more information, see Configure flexible algorithm affinities.

router isis CORE
  is-type level-2-only
  net 49.0001.0000.0000.0002.00
  log adjacency changes
    affinity-map b33 bit-position 33
    affinity-map red bit-position 1
    affinity-map blue bit-position 5
    flex-algo 128
    priority 228
    advertise-definition
    affinity exclude-any blue indigo violet black
  !
Note

Similar to affinity maps, flexible algorithms can also use Shared Risk Link Group (SRLG) exclusion constraints to prune links from the topology. These exclusions are configured on the device and then discovered by Crosswork Network Controller. For detailed configuration and visualization steps, see Configure and visualize flexible algorithm SRLG exclusion.