Time Synchronization issue

Hi Guys,

Having in our organization two DCs in VM (vmware). In DC (PDC) getting below events event id 50. 

The time service detected a time difference of greater than 5000 milliseconds for 900 seconds. The time difference might be caused by synchronization with low-accuracy time sources or by suboptimal network conditions. The time service is no longer synchronized and cannot provide the time to other clients or update the system clock. When a valid time stamp is received from a time service provider, the time service will correct itself

When i check with command w32tm /query /status getting below output.

C:\Users\w32tm /query /status
Leap Indicator: 3(last minute has 61 seconds)
Stratum: 3 (secondary reference - syncd by (S)NTP)
Precision: -6 (15.625ms per tick)
Root Delay: 0.4493613s
Root Dispersion: 0.2010621s
ReferenceId: 0x7B6CE106 (source IP:  123.108.225.6)
Last Successful Sync Time: 5/21/2015 1:02:26 PM
Source: 1.asia.pool.ntp.org,0x1
Poll Interval: 6 (64s)

When i check on secondary DC (no roles) same command.

C:\Users\>w32tm /query /status
Leap Indicator: 0(no warning)
Stratum: 4 (secondary reference - syncd by (S)NTP)
Precision: -6 (15.625ms per tick)
Root Delay: 0.4801178s
Root Dispersion: 1.0339886s
ReferenceId: 0x0A0A161F (source IP:  10.10.22.31)
Last Successful Sync Time: 5/21/2015 12:59:30 PM
Source: DC-01.domain.com
Poll Interval: 10 (1024s)

Kindly need to suggestion to overcome this problem. It was working since long time. But since yesterday night getting this events.

Thanks & Regards