> ## Documentation Index
> Fetch the complete documentation index at: https://docs.aviatrix.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Aviatrix Service Time Synchronization Policy

> Aviatrix Controllers and Gateways rely on predefined Network Time Protocol (NTP) sources to ensure accurate system time. Manual configuration of custom NTP sources is not supported.

Aviatrix Controllers and Gateways rely on predefined Network Time Protocol (NTP)
sources to ensure accurate system time. Manual configuration of custom NTP
sources is not supported.

## NTP Behavior

### Controller Deployed in AWS

Aviatrix Controller deployed in AWS environments use the Amazon Time Sync
Service at 169.254.169.123. See
[Amazon Time Sync Service](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/set-time.html)
for more information.

This service is automatically configured, requires no internet access, and is
available via a link-local IP address on all Amazon EC2 instances.

### Controller Deployed in Other Cloud Providers

Aviatrix Controller deployed outside of AWS (such as in Azure or Google Cloud)
use the following public NTP servers by default:

* pool.ntp.org — Public cluster of internet-based NTP servers

* 1.ubuntu.pool.ntp.org

* 2.ubuntu.pool.ntp.org

* 3.ubuntu.pool.ntp.org

* ntp.ubuntu.com

These servers are automatically used by the Controller for time synchronization.
Manual configuration is not supported.

## Gateway Synchronization

All Aviatrix Gateways synchronize their system time with the associated
Controller. Gateways do not query external NTP sources directly.