我有两个 internap NTP 服务器，我将它们设置在 Cisco 路由器上，但这就是我得到的。
R1#show ntp associations
address ref clock st when poll reach delay offset disp
*~10.1.1.50 129.6.15.28 2 4 64 377 0.764 -26.612 1.962
+~10.1.1.51 129.6.15.28 2 10 64 377 0.766 -18.581 1.946
* sys.peer, # selected, + candidate, - outlyer, x falseticker, ~ configured
地位：
R1#show ntp status
Clock is unsynchronized, stratum 3, reference is 10.1.1.50
nominal freq is 250.0000 Hz, actual freq is 250.0000 Hz, precision is 2**10
ntp uptime is 85000 (1/100 of seconds), resolution is 4000
reference time is DB1E7441.2B020CC0 (12:22:25.168 EDT Wed Jun 29 2016)
clock offset is -27.2765 msec, root delay is 78.64 msec
root dispersion is 37.11 msec, peer dispersion is 1.95 msec
loopfilter state is 'FREQ' (Drift being measured), drift is 0.000000000 s/s
system poll interval is 64, last update was 37 sec ago.
但它显示正确的时间，为什么show ntp status显示 unsynchronized？
R1#show clock
.12:23:41.217 EDT Wed Jun 29 2016
编辑
!
ntp server vrf Mgmt-intf 10.1.1.50
ntp server vrf Mgmt-intf 10.1.1.51
!
clock timezone EST -5 0
clock summer-time EDT recurring
!
问题：
我们有两个NTP服务器NTP1与NTP2公共NTP服务器和NTP服务器同步的时间，我应该把两个不同的公共NTP服务器列表NTP1＆NTP2服务器或应该是两个ntp1和NTP2服务器相同的公共NTP名单上，什么是最好的做法为了那个原因？
更新：
输出：
R1#show ntp associations detail
10.1.1.50 configured, ipv4, sane, valid, stratum 2
ref ID 199.102.46.79 , time DB1E94EB.26269DEA (14:41:47.149 EDT Wed Jun 29 2016)
our mode client, peer mode server, our poll intvl 512, peer poll intvl 512
root delay 29.98 msec, root disp 33.12, reach 377, sync dist 54.98
delay 0.14 msec, offset 27.2130 msec, dispersion 1.08, jitter 0.97 msec
precision 2**19, version 4
assoc id 37176, assoc name 10.5.3.60
assoc in packets 154, assoc out packets 155, assoc error packets 0
org time 00000000.00000000 (19:00:00.000 EST Thu Dec 31 1899)
rec time DB1E95F8.319EEF80 (14:46:16.193 EDT Wed Jun 29 2016)
xmt time DB1E95F8.319EEF80 (14:46:16.193 EDT Wed Jun 29 2016)
filtdelay = 0.84 0.84 0.85 0.14 0.15 0.84 0.84 0.79
filtoffset = 27.25 27.41 26.89 27.21 27.35 27.18 27.11 27.16
filterror = 0.97 1.00 1.03 1.06 1.09 1.12 1.15 1.18
minpoll = 6, maxpoll = 10
10.1.1.51 configured, ipv4, our_master, sane, valid, stratum 2
ref ID 199.102.46.79 , time DB1E937E.A19C2C7C (14:35:42.631 EDT Wed Jun 29 2016)
our mode client, peer mode server, our poll intvl 512, peer poll intvl 512
root delay 29.86 msec, root disp 24.49, reach 377, sync dist 47.72
delay 0.16 msec, offset 9.3404 msec, dispersion 1.08, jitter 0.97 msec
precision 2**19, version 4
assoc id 37177, assoc name 10.5.3.61
assoc in packets 154, assoc out packets 154, assoc error packets 0
org time 00000000.00000000 (19:00:00.000 EST Thu Dec 31 1899)
rec time DB1E959A.2D3A68F6 (14:44:42.176 EDT Wed Jun 29 2016)
xmt time DB1E959A.2D3A68F6 (14:44:42.176 EDT Wed Jun 29 2016)
filtdelay = 0.83 0.80 0.84 0.16 0.84 0.17 0.83 0.78
filtoffset = 9.09 9.22 9.28 9.34 9.49 9.24 9.60 8.85
filterror = 0.97 1.00 1.03 1.06 1.09 1.12 1.15 1.18
minpoll = 6, maxpoll = 10