VMware Photon Appliances Stuck in NTP .INIT. State (reach = 0)Symptoms

Products

• VMware vCenter Server

Issue/Introduction

•  When querying the Network Time Protocol (NTP) status (ntpq -p) on VMware Photon OS appliances, the configured remote NTP servers fail to synchronize and remain stuck in the .INIT. state.
  root@<vc_fqdn> [ ~ ]# ntpq -p
       remote      refid           st t when poll reach   delay   offset  jitter
==============================================================================
 xx.xx.x.xxx     .INIT.          16 u   46   64    0    0.000   +0.000   0.000
 xx.xx.x.xxx     .INIT.          16 u   45   64    0    0.000   +0.000   0.000
  
  
• Additionally, running ntpq -c as displays the reach status as no and the condition as reject:
  root@<vc_fqdn>[ ~ ]# ntpq -c as
ind assid status  conf reach auth condition  last_event cnt
===========================================================
  1 10483  8011   yes    no  none    reject    mobilize  1
  2 10484  8011   yes    no  none    reject    mobilize  1
  
  

Environment

VMware Photon OS (commonly underlying appliances like vCenter Server, SDDC Manager and vRealize/Aria suite components)

Cause

The .INIT. state paired with a reach value of 0 (or no) indicates that the Photon OS NTP client is sending time synchronization requests, but it is not receiving any valid responses from the upstream NTP server.
This usually happens for one of two reasons:

• Network or Firewall Restrictions: UDP Port 123 traffic is being blocked between the client and the server.
• NTP Server Configuration: The upstream NTP server is actively rejecting or ignoring the requests. This frequently happens if the server requires specific polling interval parameters that the client is not currently meeting.

Resolution

To resolve this issue, engage with your network or system administration team to perform the following checks:

1. Adjust NTP Server Polling Settings (Recommended Fix)
   In many environments with managed NTP server appliances, the server may drop requests if it isn't configured to handle the client's default polling intervals.
   
   - Navigate to your NTP server's Management/Monitoring settings.
   - Locate the setting labeled Set polling interval for ntpd client.
   - Check the box to enable this feature. This allows the server to properly negotiate and accept the polling requests originating from the Photon appliance.
   
   
2.  Verify Network Connectivity
   Ensure that there is no network disruption and that traffic over UDP Port 123 is allowed bidirectionally between the Photon OS appliance's IP address and the remote NTP server.
   
   
3. Check NTP Server Logs
   If the issue persists after updating the polling settings and confirming firewall rules, check the upstream NTP server logs to see if it is explicitly dropping or denying requests originating from the Photon appliance's IP address.

Additional Information

NTP was resolved by enabling the following setting on the NTP server: Set polling interval for ntpd client: