Accessing the ESXi host through the Host Client UI fails with error: "503 Service Unavailable"

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:
After upgrading from ESXi 5.x to ESXi 6.0 or later, you experience these symptoms:

• Logging in or accessing the ESXi host through the Host Client UI fails.
• You see an error similar to:
  
  503 Service Unavailable (Failed to connect to endpoint: [N7Vmacore4Http16LocalServiceSpecE:0x1f0daf08] _serverNamespace = /ui _isRedirect = false _port = 8308).

Environment

VMware vSphere ESXi 6.5
VMware vSphere ESXi 6.0
VMware vSphere ESXi 6.7

Resolution

1. Log in to the affected ESXi host through SSH.
2. Take a backup of the /etc/vmware/rhttpproxy/endpoints.conf file by running this command:
   
   cp /etc/vmware/rhttpproxy/endpoints.conf /etc/vmware/rhttpproxy/endpoints.bkp
    
3. Open the endpoints.conf file using a text editor. For more information on using a text editor, see Editing files on an ESX host using vi or nano (1020302).
   
   For example:
   
   vi /etc/vmware/rhttpproxy/endpoints.conf
    
4. Delete the entry "/ui local 8308 redirect allow" from the endpoints.conf file.
   
   For example, delete the highlighted entry from the endpoints.conf file:
   
   / local 8309 redirect allow
   /cgi-bin local 8309 redirect allow
   /client/clients.xml local 8309 allow allow
   /fdm local 9089 reject allow
   /folder local 8309 redirect allow
   /guestFile local 8309 redirect allow
   /ha-nfc local 12001 allow allow
   /host local 8309 redirect allow
   /mob namedpipe /var/run/vmware/proxy-mob redirect allow
   /mobfdm local 9090 redirect allow
   /nfc local 12000 allow allow
   /screen local 8309 redirect allow
   /sdk local 8307 redirect allow
   /sdkTunnel namedpipetunnel /var/run/vmware/proxy-sdk-tunnel allow reject
   /tmp local 8309 redirect allow
   /ui local 8308 redirect allow
   /vpxa local 8089 reject allow
   /wsman local 8889 redirect allow
    
5. Save and close the endpoints.conf file.
6. Restart the rhttpproxy service by running this command:
   
   /etc/init.d/rhttpproxy restart

For more information refer to VMware Host Client 1.0  release notes
Refer to vSphere 6.5 documentation
Refer to vSphere 6.7 documentation

Additional Information

Editing files on an ESX host using vi or nano

Impact/Risks:
None