HCX site pairing failed with error 503 Service Unavailable

Products

• VMware HCX

Issue/Introduction

• HCX site pairing failed with error 503 Service Unavailable.
  
• Proxy has configured in HCX admin UI.

Environment

VMware HCX

Cause

HCX proxy configuration causing local outbound https request failed, results in HCX site pairing failure.

HCX Manager uses proxy server configuration to send ALL outbound HTTPS requests to the proxy server configured in the environment.
When proxy server is configured, All local connections must be explicitly excluded from proxy operation. Proxy Exclusions field can be used to submit IP/FQDNs belongs to vCenter Server, ESXi Server, NSX Manager, IX Appliance/HBR server etc. 

Resolution

 - Configure exclusion list in proxy settings

1. Log in to the management interface: https://hcx-ip-or-fqdn:9443.
2. Navigate to the Administration tab, and select Proxy.
3. Configure Proxy Exclusions to add all local connections.