Tier-1 Advertised Routes Not Updating on Tier-0 After Transit Subnet Change in NSX-T Stateful Active-Active Deployment

Products

• VMware NSX

Issue/Introduction

• For tier-0 Stateful Active-Active, after changing the tier0-tier1 transit subnets, tier-1 advertised routes are not updated on tier-0 on few edge nodes.
• North-South traffic flowing through the affected edge nodes will be disrupted or impacted due to incorrect routing information.

Environment

VMware NSX 4.x

NSX 9.0.x

Cause

This problem is identified as a timing issue within the product code.
When transit subnet of a Stateful Active-Active Tier-0 is updated, transit subnet of all the Tier-1 router link ports of a Tier-1 gateway (connected to that Stateful Active-Active Tier-0) are not updated in the same transaction.
For the tier-1 router link ports that are updated earlier, route advertisement happens and for the tier-1 router link ports that are updated later (after tier-0 router link port update), route advertisement does not happen.

Resolution

Perform a 'reprocess' action on the affected Tier-1 Gateway 

POST https://<mgr-ip>/policy/api/v1/infra/tier-1s/<t1-id>?action=reprocess&amp;enforcement_point_path=/infra/sites/default/enforcement-points/default

Permanent fix will be available in NSX-T future release