Alibaba Cloud ECS provides standard intranet NTP servers, which you can access from your instances. We also provide external NTP services for instances that need the Internet access.
Intranet and Internet NTP servers
To counterbalance the leap seconds in our world, ECS provides free of charge, highly
accurate, and reliable NTP service for both classic network- and VPC-Connected instances.
Among the NTP servers, the ntp.cloud.aliyuncs.com achieves nearly zero difference of atomic reference by synchronizing with satellite
services. See the following table for the NTP servers provided by Alibaba Cloud ECS.
| Classic network intranet | VPC intranet | Internet |
|---|---|---|
| - | ntp.cloud.aliyuncs.com | ntp1.aliyun.com |
| ntp1.cloud.aliyuncs.com | ntp7.cloud.aliyuncs.com | ntp2.aliyun.com |
| ntp2.cloud.aliyuncs.com | ntp8.cloud.aliyuncs.com | ntp3.aliyun.com |
| ntp3.cloud.aliyuncs.com | ntp9.cloud.aliyuncs.com | ntp4.aliyun.com |
| ntp4.cloud.aliyuncs.com | ntp10.cloud.aliyuncs.com | ntp5.aliyun.com |
| ntp5.cloud.aliyuncs.com | ntp11.cloud.aliyuncs.com | ntp6.aliyun.com |
| ntp6.cloud.aliyuncs.com | ntp12.cloud.aliyuncs.com | ntp7.aliyun.com |
Other public services of Alibaba Cloud ECS
See the following list for some public services provided by Alibaba Cloud ECS.
| Public service | Description |
|---|---|
| Public DNS: 223.5.5.5 / 223.6.6.6 | Domain name: http://www.alidns.com |
Open source images: http://mirrors.aliyun.com |
Update frequency: The image files are updated at everyday 02:00−04:00 (UTC+8:00), including a lot of Linux distributions and open source applications. |