Debian NTP服务器不能同步

Question

我有Debian 8和NTP服务器。问题是，NTP服务器只使用“自”IP服务器，我不知道为什么

ntpq -p：

 remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
 10.1.100.11     .INIT.          16 u    -   64    0    0.000    0.000   0.000

ntp.conf：

# /etc/ntp.conf, configuration for ntpd; see ntp.conf(5) for help
tinker panic 0 

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


# You do need to talk to an NTP server or two (or three).
#server ntp.your-provider.example

# pool.ntp.org maps to about 1000 low-stratum NTP servers.  Your server will
# pick a different set every time it starts up.  Please consider joining the
# pool: <http://www.pool.ntp.org/join.html>
#server 0.debian.pool.ntp.org iburst
#server 1.debian.pool.ntp.org iburst
#server 2.debian.pool.ntp.org iburst
#server 3.debian.pool.ntp.org iburst

server 0.pool.ntp.org
server 1.pool.ntp.org
server 2.pool.ntp.org
server 3.pool.ntp.org


#server tempus1.gum.gov.pl iburst
#server tempus2.gum.gov.pl 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
restrict -6 default kod notrap nomodify nopeer noquery
restrict 192.168.11.0 mask 255.255.255.0 nomodify notrap
restrict 192.168.10.0 mask 255.255.255.0 nomodify notrap
restrict 192.168.255.0 mask 255.255.255.0 nomodify notrap
restrict 10.0.0.0 mask 255.0.0.0 nomodify notrap

# Local users may interrogate the ntp server more closely.
restrict 127.0.0.1
restrict ::1

# 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

Answer 1

下面是与您的配置(不包括注释)的默认Debian 8 NTP配置的清理后的差异：

0a1
> tinker panic 0 
1a3
> statsdir /var/log/ntpstats/
6,9c8,11
< server 0.debian.pool.ntp.org iburst
< server 1.debian.pool.ntp.org iburst
< server 2.debian.pool.ntp.org iburst
< server 3.debian.pool.ntp.org iburst
---
> server 0.pool.ntp.org
> server 1.pool.ntp.org
> server 2.pool.ntp.org
> server 3.pool.ntp.org
11a14,17
> restrict 192.168.11.0 mask 255.255.255.0 nomodify notrap
> restrict 192.168.10.0 mask 255.255.255.0 nomodify notrap
> restrict 192.168.255.0 mask 255.255.255.0 nomodify notrap
> restrict 10.0.0.0 mask 255.0.0.0 nomodify notrap
13d18
< restrict ::1

所有这些变化都不可能导致上游连通性问题。当我将您的配置放在VM上时，它会产生一个工作配置(虽然我建议保留默认的服务器行，而不是替换)。

因此，不管是什么引起了你的问题，似乎都是在这台机器的外部。关于缩小这一问题的一些建议：

确认DNS正确解析了NTP服务器名(即不解析到服务器)：

host 0.pool.ntp.org
grep 0.pool.ntp.org /etc/hosts

这些重写最有可能导致您的问题，因为您的配置中似乎没有其他任何东西会导致您的系统使用10.1.100.11作为NTP服务器。

检查是否有ntpdate或sntp连接到NTP池：

ntpdate -d 0.pool.ntp.org
sntp 0.pool.ntp.org

或者重新启动ntp，同时使用tcpdump、tshark或wireshark嗅探数据包：

tshark -i eth0 -n -f 'udp port 123' &
service ntp restart

如果其中任何一个都失败了，或者您看到您的请求发出而没有回复，那么可能会有防火墙阻塞您的请求。

如果您需要进一步帮助跟踪它，请发布以下内容的输出：

tail /var/log/ntpstats/peerstats