为什么 ntpq -p 和 ntpstat 始终显示不同的时间差和层值输出？

Question

为什么时间差和阶层价值的输出总是不同ntpq -p？ntpstat“ntpstat 结果中未指定”是什么意思，该相信哪一个？

请参考这个输出：

1. ntpstat

   synchronised to unspecified at stratum 4
   time correct to within 17 ms polling server every 8s
   

2. ntpq -p

       remote           refid      st t when poll reach   delay   offset   jitter
   *130.246.71.4 139.143.5.31     3 u    4    8  377   0.1520   0.0222   0.0249
    3. ntpq -p
   
        remote           refid      st t when poll reach   delay   offset   jitter
   +139.143.5.30 139.143.45.169   2 u    6    8  377   4.6551  -0.0357   0.0445
   *139.143.5.31 139.143.45.169   2 u    4    8  377   4.7170   0.0087   0.0240
   

3. ntpstat

   synchronised to unspecified at stratum 3
   time correct to within 17 ms
   polling server every 8 s