Some NTP servers in China are experiencing issues, with their time running about five minutes behind the actual time

Client Configuration and Development
1

Some NTP servers in China are experiencing issues, with their time running about five minutes behind the actual time. Can somebody tell me how and when to fix it.

2

Are they pool NTP servers, ie. you access them via pool.ntp.org? Do you have their IP addresses?

3

1.cn.pool.ntp.org/193.182.111.142:123

There was a problem with this server yesterday; I’m not sure if there are any problems with other servers.

4

Yes, true. This server’s score page links to a CSV file which can be filtered to some specific monitor. searn1-3strqkc is the closest and with it the CSV says:

1766368082,2025-12-22 01:48:02,-0.000058154,1,-23.837263107,130,searn1-3strqkc,0.427,,
1766367610,2025-12-22 01:40:10,-0.000116208,1,-26.144487381,130,searn1-3strqkc,0.402,,
1766367138,2025-12-22 01:32:18,-0.000051954,1,-28.573143005,130,searn1-3strqkc,0.577,,
1766366663,2025-12-22 01:24:23,-181.778363862,-4,-31.12962532,130,searn1-3strqkc,0.367,,
1766366258,2025-12-22 01:17:38,-215.563936257,-4,-28.557500839,130,searn1-3strqkc,0.607,,
1766365909,2025-12-22 01:11:49,-244.591759822,-4,-25.850000381,130,searn1-3strqkc,0.623,,
1766365529,2025-12-22 01:05:29,-276.141869779,-4,-23,130,searn1-3strqkc,0.6,,
1766365101,2025-12-22 00:58:21,-311.961614687,-4,-20,130,searn1-3strqkc,0.618,,
1766364725,2025-12-22 00:52:05,,-5,14,130,searn1-3strqkc,0,,network: i/o timeout
1766364381,2025-12-22 00:46:21,0.000073188,1,20,130,searn1-3strqkc,0.463,,
1766364052,2025-12-22 00:40:52,0.000111341,1,20,130,searn1-3strqkc,0.462,,
1766363719,2025-12-22 00:35:19,-0.000031291,1,20,130,searn1-3strqkc,0.573,,

This means the time was indeed 5 minutes (311.96 seconds) off at some point. The server got removed from the pool at the time (at around 01:00:37 or shortly thereafter), but was later on reinstated when the situation normalized.

It’s always a good idea to have multiple time sources configured so that if one time source acts up, the other time sources can be used to determine the one time source should be ignored. chrony and ntpd do this pretty much out of the box.

5

Yes, it has been restored; Thank you, you are very professional. We are considering strengthening according to your strategy.