OSPF Configurations on Many NE40Es Are Missing When an SDN-WAN Controller Is Used

In the testing environment of a financial customer, service cutover on NE40Es is simulated. An error occurs in the test, and traffic forwarding fails.

1. Check BGP routes. It is found that BGP routes are missing.

2. Check OSPF routes. It is found that OSPF routes are missing.

3. Check OSPF configurations. It is found that OSPF configurations are missing.

4. Obtain operation logs of routers. It is found that the controller has delivered the operation of deleting the OSPF configuration through NETCONF.

5. Check the AC controller operation logs. It is found that the AC controller has performed automatic reconciliation and the operation of deleting OSPF configuration has been delivered during reconciliation.

6. Perform reconciliation on the AC controller. It is found that the OSPF configuration on the forwarder is different from that saved on the controller. The controller incorrectly determines that inconsistent OSPF configuration needs to be restored through reconciliation and therefore delivers the OSPF configuration.

When OSPF configuration is changed on a router, the controller incorrectly determines that the configuration is not delivered in an end-to-end manner. The controller simply performs reconciliation and changes the OSPF configuration on the router in overriding mode. As a result, the OSPF configuration is missing on the router, affecting network connectivity.

Workaround: Disable the NETCONF write permissions granted to the AC controller by routers.

Solution: Upgrade the patch V300R001C10SPC200 of the AC controller.

If the AC controller implements traffic optimization only, you are advised to disable the NETCONF write permissions granted to the AC controller by routers.