Realization error occurs when changing Tier-1 Gateway to Distributed Only from T1 Service Router when Multicast is enabled

Products

• VMware NSX

Issue/Introduction

• NSX Tier-1 Gateway is in Active-Standby with Multicast enabled
• Edit the Tier-1 Gateway
• Change the HA Mode from Active-Standby to Distributed Only without changing Multicast, and click Save
• This results in Status: Failed
• A realization error shows:
  [error_code]=11262, module_name=ROUTING,
error_message='[Routing] Removal of edge cluster from Tier1 logical router is not allowed as multicast is enabled on it.']

Environment

VMware NSX 4.x

Cause

• This is a known issue that is resolved in 4.2.0.
• Manager fails to realize T1 gateway HA Mode to Distributed Only when multicast enabled as a locale-service

Resolution

When running into this realization error, there is a chance that your Tier-1 Gateway will subsequently show as showing Status: Failed, or it could remain completely healthy outside of the inability to change the HA Mode to Distributed Only.

If the Tier-1 Gateway is not in a Failed status:

1. Edit the Tier-1 GW and disable Multicast
2. Click Save
3. Edit the Tier-1 GW again, and change the HA Mode to Distributed Only 
4. Click Save

If the Tier-1 Gateway is in a Failed status as a result of attempting to change HA Mode from Active-Standby to Distributed Only:

1. Edit the Tier-1 GW and re-enable multicast (ensure multicast is first enabled on the connected T0)
   (While in a Failed status, multicast may show as disabled in the UI and would need to be enable again)
2. Click Save
3. Edit the Tier-1 GW and disable multicast
4. Click Save
5. Edit the Tier-1 GW and change change the HA Mode to Distributed Only

 

In NSX 4.2.0 and above, the T1 GW can be changed to Distributed Only without first disabling multicast and it will realize correctly

Additional Information

If the T1 GW is in a Failed status and the steps above do not resolve the issue then follow these steps:

1. Enable or re-enable multicast on the corresponding T0 Gateway
2. Enable multicast on the T1 Gateway
3. Run a GET API call on locale-services for multicast: 
   GET /policy/api/v1/infra/tier-1s/<tier1-id>/locale-services/default/multicast
4. From the body of the output, copy the key labeled "multicast" and change the value from "true" to "false"
5. Run a PUT API call on locale-services to disable multicast with the key and value: "enabled": "false"
PUT  /policy/api//v1/infra/tier1s/<tier1-id>/locale-services/default/multicast
   {"enabled": "false"}
6. Edit the T1 GW and change HA Mode from Active-Standby to Distributed Only
7. Edit the T0 GW and disable Multicast if applicable