Cisco Crosswork Network Controller 7.2.x Administration Guide

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Cisco Crosswork Network Controller 7.2.x Administration Guide

Troubleshooting the topology map

Updated: August 14, 2026

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This section provides common causes and recommended solutions for troubleshooting issues with the topology map, such as missing devices or incorrect network layout. Use this reference to quickly resolve topology visualization problems.

The table below lists common topology map issues, their possible causes, and suggested actions:

Issue Possible cause Recommended action
Devices do not appear on the topology map Devices are offline or unreachable Verify devices are powered on and connected to the network.
Incorrect topology layout Outdated network configuration Ensure device IP addresses, subnet masks, gateways, and DNS settings are correct.
Status shows as "unknown" or "unreachable" Network or configuration error Check device connectivity and management protocol settings.
Map does not match physical layout Devices added or removed without update Refresh the topology map after any network changes.

If the basic troubleshooting steps do not resolve your topology issue, refer these actions for further diagnosis.

Identify and correct issues that prevent Layer 2 links from appearing in the topology. For more information refer to Change L2 discovery settings.

Missing Layer 2 links typically occur if L2 discovery protocols are not enabled or required device and peer configurations are incomplete. Ensuring proper discovery settings and connectivity allows accurate network topology visualization.

Procedure

1.

From the main menu, go to Administration > Settings > System settings.
2.

Under Topology, select Discovery.

3.

Enable L2 link discovery if it is disabled, then click Save.
4.

If L2 links are still not visible, perform the following checks:

  1. Check PCE configuration:

    • Ensure the required PCE IP address is assigned to a loopback interface.

      pce
 address ipv4 198.19.1.201

    • Configure the API user required for discovery.

       api
  user cisco
   password encrypted 121A0C041104

    • Configure any required sibling PCE addresses and verify they are visible.

      sibling ipv4 11.1.201.202

  2. Verify sibling PCE connectivity:

    RP/0/RP0/CPU0:pce-1#show pce api sibling connection

    Sample output:

    Address:                   11.1.201.202
Connected:                        Yes
Input buffer size:                  0
Packets in output buffer:           0

  3. Ensure the head-end node is a PCEP peer and correctly configured:

    segment-routing
 traffic-eng
  pcc
   source-address ipv4 198.19.1.4
   pce address ipv4 198.19.1.201
   precedence 100
   pce address ipv4 198.19.1.202
   precedence 100
   report-all

  4. Verify PCEP sessions:

    • On PCE

      RP/0/RP0/CPU0:pce-1#show pce ipv4 peer 198.19.1.4

    • On PCC

    Node-4#show segment-routing traffic-eng pcc ipv4 pee

    Sample output:

    Peer address: 198.19.1.201,
  Precedence: 100, (best PCE)
  State up
  Capabilities: Stateful, Update, Segment-Routing, Instantiation, SRv6

Peer address: 198.19.1.202,
  Precedence: 100
  State up
  Capabilities: Stateful, Update, Segment-Routing, Instantiation, SRv6
5.

If L2 links still do not appear, consider rebuilding your topology. For details, see Rebuild the topology.

After completing these steps, missing Layer 2 links should be discovered and visible in the network topology view. If issues persist, rebuilding the topology may resolve configuration inconsistencies.

What to do next

Review newly discovered L2 links and confirm connectivity in the topology.

Identify and restore missing Layer 3 links by checking device health, configurations, and SR-PCE topology information.

Missing Layer 3 links can occur due to device-level issues such as hardware failure, software bugs, misconfiguration, or interference. Ensuring that devices and IGP settings are correct helps the SR-PCE learn accurate topology information.

Before you begin

Procedure

1.

From the main menu, go to Administration > Manage Provider Access.

Under Reachability column, confirm that the providers are reachable.

2.

If the L3 links are not visible:

  1. If a link is missing in the topology UI, ensure that the ISIS or OSPF neighbor relationship is up using these configurations:

    RP/0/RP0/CPU0:Node-4#show isis neighbors
    Sample output: 
    IS-IS 1 neighbors:
System Id      Interface        SNPA           State Holdtime Type IETF-NSF
Node-7         Gi0/0/0/0        *PtoP*         Up    23       L2   Capable

    RP/0/RP0/CPU0:Node-7#show isis neighbors

    Sample output:

    IS-IS 1 neighbors:
System Id      Interface        SNPA           State Holdtime Type IETF-NSF
Node-4         Gi0/0/0/1        *PtoP*         Up    22       L2   Capable

  2. Ensure that the link is configured as point-to-point: 

    router isis 1
interface GigabitEthernet0/0/0/0
  point-to-point

  3. Ensure that the link is visible in PCE:

    show pce ipv4 topology 198.19.1.4
    Sample output: 
    Node 30
  Link[2]: local address 10.4.7.4, remote address 10.4.7.7

  4. In case the L3 links are still missing, consider rebuilding your topology. Refer to Rebuild the topology.

Check error records in Topology services alarms and events report

Diagnose and resolve problems within Topology services by reviewing error records in the Alarm and Events report.

Topology services may encounter operational errors, such as missing data, communication failures, or configuration issues. These errors are captured in the Alarm and Events report, allowing you to quickly identify and address problems impacting network visibility.

Procedure

1.

From the main menu, go to Administration > Alarms.
2.

In the Source filter, enter topo to display alarms and events specific to Topology services.

The filtered Alarm Events report shows all related error records.
3.

Review the list for error records, noting any issues such as missing data or communication failures.

You will see all error records associated with Topology services, making it easier to diagnose and resolve operational problems.

What to do next

Investigate any error records found and take corrective actions as needed.

Rebuild the topology

Rebuilding the topology is a process of creating a new topology for our system. This is useful when the topology becomes inconsistent because of network problems or other unforeseen events. You should only rebuild the topology as a last resort.

The topology rebuild will refresh the topology and update the links and devices. The topology pages will not display links and devices when a rebuild is in progress. They will reappear after the rebuild is complete.

Procedure

1.

Turn the system maintenance mode on.

Choose Administration > Settings > System Settings > Maintenance mode.
2.

Begin the process of rebuilding the topology.

Under Topology, choose Maintenance and click Rebuild Topology.
3.

When the Confirm Topology Rebuild dialog box appears, click Rebuild Topology again.
4.

After links and devices reappear on the topology map indicating that the topology has been rebuilt, turn the maintenance mode off.

Choose Administration > Settings > System Settings > Maintenance mode.
5.

(Optional)You can view detailed events about the rebuild.

  1. Choose Alerts > Alarm and Events.

  2. From the Show drop-down list, select Events.

  3. From the Category drop-down list, select Network.