Post brownfield import, network outage or intermittent connectivity issues are observed while using NSX Networks (Segments/LogicalSwitches) over LACP-configured DVSes

Products

• VMware Cloud Foundation

Issue/Introduction

1. After brownfield import of vCenter, network outage or intermittent network flapping is observed while using NSX Networks (Segments/LogicalSwitches) over LACP-configured DVSes.
   
   
2. The NSX Network's effective teaming policy has: a. Multiple LACP/LAG uplinks under the Active list. OR b. Combination of LACP/LAG and regular uplinks under the Active list.

Environment

VMware Cloud Foundation 9.1.0.0

Resolution

Currently there is no resolution to the issue. This will be fixed in future releases.

 

Workaround: Create a new Uplink Host Switch Profile with the correct teaming policy and uplink configuration, then update the Transport Node Profile (TNP) to reference the new profile.

Prerequisites:

1. Backup NSX Manager configuration: 
   
   Perform a fresh backup of the NSX Manager before making any changes.
   
   
2. Verify all transport nodes are in SUCCESS state: 
   
   Navigate to System > Fabric > Hosts > Clusters. - Expand the affected cluster and confirm all transport nodes show "Success" configuration status. - If any transport node is in degraded or failed state, address that first before proceeding.
   
   
3. Check for VMK migration mappings:
   
   If the Transport Nodes have VMK migration mappings configured, TNP updates will fail on hosts with powered-on VMs. In this case, place hosts in maintenance mode before updating the TNP (Reference: KB 327354). - For brownfield imported clusters, VMK migration is typically not configured, and TNP updates can proceed without maintenance mode. Note: A brief network disruption may occur as the updated configuration is reconciled on the hosts. It is recommended to perform these changes during a planned maintenance window.
   
   Steps: 1. Identify the current Uplink Host Switch Profile:
   
   a. Navigate to NSX Manager UI > System > Fabric > Profiles > Uplink Profiles.
   
   b. Identify the uplink profile created by SDDC Manager for the affected cluster's DVS. - The profile name typically follows the pattern: --uplink-profile-
   
   c. Note the current teaming policy type and active uplinks configured in this profile.
   
   Steps: 2. Determine the correct uplink configuration:
   
   a. Check the active uplinks listed in the teaming policy of the current profile.
   
   b. Identify which uplinks are LAGs and which are regular uplinks. - LAG uplinks are typically named with a LAG identifier (e.g., "lag0", "lag1"). - Regular uplinks are typically named "uplink1", "uplink2", etc.
   
   Steps 3. Create a new Uplink Host Switch Profile:
   
   a. Navigate to NSX Manager UI > System > Fabric > Profiles > Uplink Profiles > Add Profile.
   
   b. If only LAG uplinks are present: - Set Teaming Policy to FAILOVER_ORDER. - Add only one LAG as the active uplink.
   
   c. If both LAG and regular uplinks are present, or only regular uplinks:
   - Set Teaming Policy to LOADBALANCE_SRCID. - Add only the regular uplinks (excluding LAGs) as active uplinks.
   
   d. Copy the Transport VLAN setting from the original profile (if applicable).
   
   e. Save the new profile.
   
   
4.  Update the Transport Node Profile (TNP):
   
   a. Navigate to NSX Manager UI > System > Fabric > Hosts > Transport Node Profiles.
   
   b. Select the TNP associated with the affected cluster.
   
   c. Edit the TNP. d. Edit the Host Switch configuration for the affected DVS, change the Uplink Profile reference from the old profile to the newly created profile.
   
   e. Review and update the Teaming Policy Uplink Mapping to ensure the VDS uplinks are correctly mapped to the new profile's active uplinks.
   
   f. Save the TNP.
5. Verify the configuration:
   
   a. Navigate to NSX Manager UI > System > Fabric > Hosts > Clusters.
   
   b. Expand the affected cluster.
   
   c. Verify that the transport nodes show "Success" configuration status.
   
   d. If any transport nodes show "In Progress", wait for the reconciliation to complete.
   
   e. If any transport nodes show "Failed", check the error details and retry if needed.
   
   
6. Validate network connectivity:
   
   a. Confirm that network outage or flapping has been resolved on the affected hosts.
   
   b. Verify that LACP negotiation is functioning correctly on the DVS.