Problem: Servers are not connecting due to the time skew issue? And servers are shown down due to it in the HC10 control panel. How to resolve this issue? The following exception is also observed for this server down issue due to skewing of time across all servers.
Reason: To tighten the security of servers and avoid invalid hacking attempts, Microsoft has implemented a time synchronization clock maximum allowed limit of 5 minutes. If there is a difference among servers greater than 5 minutes then the servers are disallowed to communicate.
Solution: The time in UTC across all servers should be the same or the difference in time must not be greater than 5 minutes.
For Example, consider the two servers added in HC10 panel having different time zones.
In the screenshot above, the time on 2 servers is:
- Time on Server 1 is 7:13am (UTC-5)
- Time on Server 2 is 4:18am (UTC-8)
The time in UTC on both above servers should be the same or the difference in time must not be greater than 5 minutes. Now let’s calculate, the time difference for both of the above servers :
- UTC Time Calculation for first server : The time on the first server is 7:13am (UTC-5). To check its time in UTC, add 5 hours which will make it 7:13am + 5 hours = 12:13pm (UTC)
- UTC Time Calculation for second server : The time on the second server is 4:18am (UTC-8). To check its time in UTC, add 8 hours which will make it 4:18am + 8 hours = 12:18pm (UTC)
The time difference between first and second servers is : 12:18pm (UTC) - 12:13pm (UTC) = 5 minutes which is the permissible limit for successful connection of the servers. Therefore using the above formulae make sure every time, that when you change the time of your Control Server and the UTC time of this server is greater than 5 minutes then Time Skewing exception will be noticed in your HC panel under exception section and your servers will show down and would not communicate properly.