一切似乎都适用于这个命令ntpq-pn，它告诉我：
remote refid st t when poll reach delay offset jitter
==============================================================================
-184.105.182.7 216.218.254.202 2 u 54 64 377 79.218 -11.053 0.466
+69.195.159.158 208.100.0.228 3 u 65 64 377 36.752 -7.735 0.407
-74.120.81.219 128.138.140.44 2 u 64 64 377 34.972 -1.763 16.977
*45.55.102.31 98.175.203.200 2 u 61 64 377 7.723 -3.781 4.854
+91.189.94.4 193.79.237.14 2 u 60 64 377 79.423 -2.344 0.520
和ntpdate -d 192.168.1.231给我看看：
24 Mar 15:40:25 ntpdate[12564]: ntpdate [email protected] Wed Oct 5 12:34:47 UTC 2016 (1)
Looking for host 192.168.1.231 and service ntp
host found : 192.168.1.231
transmit(192.168.1.231)
transmit(192.168.1.231)
transmit(192.168.1.231)
transmit(192.168.1.231)
transmit(192.168.1.231)
192.168.1.231: Server dropped: no data
server 192.168.1.231, port 123
stratum 0, precision 0, leap 00, trust 000
refid [192.168.1.231], delay 0.00000, dispersion 64.00000
transmitted 4, in filter 4
reference time: 00000000.00000000 Thu, Feb 7 2036 1:28:16.000
originate timestamp: 00000000.00000000 Thu, Feb 7 2036 1:28:16.000
transmit timestamp: dc7ff4af.1ec5f659 Fri, Mar 24 2017 15:40:31.120
filter delay: 0.00000 0.00000 0.00000 0.00000
0.00000 0.00000 0.00000 0.00000
filter offset: 0.000000 0.000000 0.000000 0.000000
0.000000 0.000000 0.000000 0.000000
delay 0.00000, dispersion 64.00000
offset 0.000000
24 Mar 15:40:33 ntpdate[12564]: no server suitable for synchronization found
在最后一行“找不到适合同步的服务器《如何让它变成》成立”
即使当我尝试使用这个命令时国家发展委员会：
root@Lab-X230:/home/igor# ntpdc
ntpdc> peers
localhost: timed out, nothing received
***Request timed out
root@Lab-X230:/home/igor# sudo vim /etc/ntp.conf
# /etc/ntp.conf, configuration for ntpd; see ntp.conf(5) for help
driftfile /var/lib/ntp/ntp.drift
# Enable this if you want statistics to be logged.
#statsdir /var/log/ntpstats/
statistics loopstats peerstats clockstats
filegen loopstats file loopstats type day enable
filegen peerstats file peerstats type day enable
filegen clockstats file clockstats type day enable
# Specify one or more NTP servers.
# Use servers from the NTP Pool Project. Approved by Ubuntu Technical Board
# on 2011-02-08 (LP: #104525). See http://www.pool.ntp.org/join.html for
# more information.
#pool 0.ubuntu.pool.ntp.org iburst
#pool 1.ubuntu.pool.ntp.org iburst
#pool 2.ubuntu.pool.ntp.org iburst
#pool 3.ubuntu.pool.ntp.org iburst
# Use Ubuntu's ntp server as a fallback.
#pool ntp.ubuntu.com
server 0.ubuntu.pool.ntp.org iburst
server 1.ubuntu.pool.ntp.org iburst
server 2.ubuntu.pool.ntp.org iburst
server 3.ubuntu.pool.ntp.org iburst
server ntp.ubuntu.com iburst
# Access control configuration; see /usr/share/doc/ntp-doc/html/accopt.html for
# details. The web page <http://support.ntp.org/bin/view/Support/AccessRestrictions>
# might also be helpful.
#
# Note that "restrict" applies to both servers and clients, so a configuration
# that might be intended to block requests from certain clients could also end
# up blocking replies from your own upstream servers.
# By default, exchange time with everybody, but don't allow configuration.
restrict -4 default kod notrap nomodify nopeer noquery limited
"/etc/ntp.conf" 74L, 2669C 26,1 Top
#
# Note that "restrict" applies to both servers and clients, so a configuration
# that might be intended to block requests from certain clients could also end
# up blocking replies from your own upstream servers.
# By default, exchange time with everybody, but don't allow configuration.
restrict -4 default kod notrap nomodify nopeer noquery limited
restrict -6 default kod notrap nomodify nopeer noquery limited
# Local users may interrogate the ntp server more closely.
#restrict default ignore
#restrict 127.0.0.1 mask 255.255.255.255
restrict 127.0.0.1
restrict ::1
# Needed for adding pool entries
restrict source notrap nomodify noquery
# Clients from this (example!) subnet have unlimited access, but only if
# cryptographically authenticated.
#restrict 192.168.123.0 mask 255.255.255.0 notrust
# If you want to provide time to your local subnet, change the next line.
# (Again, the address is an example only.)
#broadcast 192.168.123.255
# If you want to listen to time broadcasts on your local subnet, de-comment the
# next lines. Please do this only if you trust everybody on the network!
#disable auth
#broadcastclient
#Changes recquired to use pps synchonisation as explained in documentation:
#http://www.ntp.org/ntpfaq/NTP-s-config-adv.htm#AEN3918
#server 127.127.8.1 mode 135 prefer # Meinberg GPS167 with PPS
#fudge 127.127.8.1 time1 0.0042 # relative to PPS for my hardware
#server 127.127.22.1 # ATOM(PPS)
#fudge 127.127.22.1 flag3 1 # enable PPS API
说明应遵循 5.1.3.3 中的链接 http://www.ntp.org/ntpfaq/NTP-s-algo.htm#Q-ACCURATE-CLOCK， 例如：
ntpdc> loopinfo
offset: -0.000102 s
frequency: 16.795 ppm
poll adjust: 6
watchdog timer: 63 s
答案1
基本上，这是因为ntpq使用“模式 6”查询和ntpdc使用“模式 7”查询（这两个名称都来自 NTP 协议中的字段）。模式 7 查询 ( 和ntpdc) 是默认情况下已弃用并禁用。
尝试使用ntpq命令rv、kerninfo和sysinfo来提供所有信息（以及更多信息）。如果您必须使用ntpdc，那么您可以重新启用模式 7（上面链接中的说明，但要注意它是过去安全问题的根源）。
至于ntpdate -d 192.168.1.231，假设这是该 NTP 服务器的 IP 地址，我建议检查防火墙规则。您的配置中似乎没有noserve或没有。ignore另请注意，这ntpdate大部分已被弃用，并且ntpd有一个-q替代选项。