Gateway Cutover: From Source Site to Target Site Using HCX

Gateway cutover is a critical activity that marks the final phase of the migration process. It is performed only after all virtual machines (VMs) and workloads have been successfully migrated from the source site to the target data center. This ensures minimal disruption and seamless continuity of operations.

In this blog post, we will demonstrate the gateway cutover process using HCX (Hybrid Cloud Extension) and explore all the steps involved in executing it effectively.

Why Gateway Cutover Matters:

Gateway cutover is essential for ensuring that the migrated workloads at the target site operate with optimal performance. Without this step, workloads may still rely on the source site for their network gateway, leading to increased latency and degraded performance.

Observing the Need for Gateway Cutover:

In the screenshot below, you can see an example where a VM has been migrated to the target site, but its gateway is still located at the source site. This setup results in high latency:

As shown, the latency is significantly higher because the network traffic is routed back to the source site for gateway access. This reinforces the importance of completing the gateway cutover.

Now, we will walk through the gateway cutover process using HCX:

Pre-requisites:

• No workloads/VMs in source site should/is still connected to vlan/Segment, that you're planning to do gateway cutover for.

• Perform health-check from HCX Connector, and verify the status, status should be "ok".

Procedure step-by-step:

1. Login to HCX Connector UI (source site port 443).

2. Go to Services > Network Extension.

3. Validate & verify the network status is healthy (ok).

4. Check the box for network you want to unextend.

5. Click on Unextend Networks.

   
   

   

   
   

6. Check the box Connect cloud network to cloud edge gateway after unextending and click on Unextend.

   
   

   

7. Monitor the status for progress and completion.

   
   

   

   
   

8. Login to Target site NSX Manager, and verify the status/health of unextended network. It should be connected to "t1" as can see below in screenshot.

   
   

Post-Cutover Validation:

• Verifying successful cutover and ensuring workloads operate as expected.

Conclusion:

By following these steps, you can effectively & seamlessly perform Gateway Cutover of the extended network from source datacenter to target datacenter.

!Best of luck!