Resolving Health Issues on Network Extensions (NE)

Products

• VMware HCX

Issue/Introduction

Network Extensions (NE) may experience health degradation and network inconsistencies, resulting in:

• Virtual machines becoming unreachable on extended segments
• Network connectivity failures
• Failed ping requests
• Routing inconsistencies through NSX gateways
• Network Extension showing unhealthy status

Environment

• HCX Network Extensions
• NSX-T environment
• Extended network segments
• HCX HA Group configuration
• Network configurations with or without MON (Multisite Overlay Networks) enabled

Cause

Network Extension health issues can occur due to several factors

1. Network Extension state becoming unsynchronized
2. HA Group synchronization issues
3. Complex network configurations, especially when MON is enabled
4. Network Extension deployment inconsistencies
5. Underlying network state mismatches

Resolution

Service Mesh Verification and Diagnostics

Important: Service Mesh operations must be performed from the source site (HCX Connector) only, not from the cloud destination side.

1. Log in to the HCX Manager at the source site (https://hcxmgr-ip-or-fqdn:443)
2. Run Service Mesh Diagnostics:
   • Navigate to Interconnect > Service Mesh
   • Click "Run Diagnostics" to perform health check
   • Review diagnostic results thoroughly
   • Optionally, view current topology via Service Mesh > View Topology
3. Check if Resync is Required:
   • Review recent changes to Compute Profile, Network Profile, or Service Mesh
   • If no recent changes, proceed directly to Regular Redeployment
   • If changes exist, continue with Resync process
4. If Resync is Required:
   • Click "Resync" button
   • Note: Resync should only be used in healthy Service Mesh environments
   • Do not use Resync for troubleshooting Service Mesh error states
   • Wait for Resync operation to complete
   • Verify changes appear in Service Mesh configuration

Initial Network Checks

1. Verify basic connectivity
2. Check NSX configuration status
3. Review recent network changes
4. Confirm no active migrations on affected segments

Regular Redeployment Process

Option 1 - HA Group Level Redeployment

1. Access the HCX interface from source site
2. Navigate to the affected HA Group
3. Select "Redeploy" for Network Extensions
4. Monitor redeployment progress
5. Verify health status after completion

Option 2 - Individual Network Extension Redeployment

1. Access the HCX interface from source site
2. Locate the specific Network Extension experiencing issues
3. Execute "Redeploy" operation
4. Monitor the redeployment process
5. Verify health status after completion

Validation Steps

1. Verify Network Extension health status
2. Confirm HA Group status is healthy
3. Test virtual machine connectivity
4. Validate network routing functionality
5. Ensure consistent network behavior across all extended segments

If issues persist after trying these steps, please reach out to Broadcom Support for additional assistance.

Additional Information

Best Practices for Maintaining Network Extension Health

• Always perform Service Mesh operations from the source site
• Run Service Mesh Diagnostics before making any changes
• Regularly monitor Network Extension health status
• Review HA Group synchronization status
• Follow recommended network extension configurations
• When using MON, pay special attention to routing configurations
• Implement proper network segmentation
• Perform regular health checks and maintenance