All Products
Search
Document Center

Elastic Compute Service:Alibaba Cloud NTP servers

Last Updated:Sep 01, 2023

This topic describes Alibaba Cloud Network Time Protocol (NTP) servers. Alibaba Cloud provides internal and public NTP servers to synchronize the local time of Elastic Compute Service (ECS) instances in networks.

NTP servers

NTP is used to synchronize computer time in a network. ECS provides high-precision NTP servers for your use. The ntp.cloud.aliyuncs.com server offers a distributed NTP service that uses Stratum 1 servers. Stratum 1 servers are suitable for industries that require precise timing, such as finance, communication, scientific research, and astronomy. The NTP service is also used to synchronize the local time between ECS instances and other cloud services.

The consistency of time and time zones in ECS is crucial because it can affect task execution results. For example, when you update a database or analyze logs, the time sequence has a significant impact on the results. When you run business on ECS instances, you must standardize the time zones of all involved instances to prevent issues such as logical confusions and network request errors.

Domain names of Alibaba Cloud NTP servers

The following table describes the domain names of Alibaba Cloud NTP servers in various networks. These domain names support only IPv4.

Classic network (internal network)

Virtual private cloud (VPC) (internal network)

Internet

-

ntp.cloud.aliyuncs.com

ntp.aliyun.com

ntp1.cloud.aliyuncs.com

ntp7.cloud.aliyuncs.com

ntp1.aliyun.com

ntp2.cloud.aliyuncs.com

ntp8.cloud.aliyuncs.com

ntp2.aliyun.com

ntp3.cloud.aliyuncs.com

ntp9.cloud.aliyuncs.com

ntp3.aliyun.com

ntp4.cloud.aliyuncs.com

ntp10.cloud.aliyuncs.com

ntp4.aliyun.com

ntp5.cloud.aliyuncs.com

ntp11.cloud.aliyuncs.com

ntp5.aliyun.com

ntp6.cloud.aliyuncs.com

ntp12.cloud.aliyuncs.com

ntp6.aliyun.com

-

-

ntp7.aliyun.com

Other public services

The following table describes other public services provided by Alibaba Cloud.

Public service

Description

Public Domain Name System (DNS): 223.5.5.5/223.6.6.6

Alibaba Cloud Public DNS Free Edition: https://www.alidns.com

Website of public images: https://developer.aliyun.com/mirror

Update frequency: Images are updated from 02:00 to 04:00 every day (UTC+8). The images contain a wide collection of Linux distributions and open-source software.

References