Один из моих серверов не может синхронизировать время с моим внутренним ntp-сервером.
Он работает для всех серверов в DMZ, кроме одного!
Вот отладка ntpdate сервера, который может синхронизировать:
host-10.254.250.52:~# ntpdate -u -d internal-ntp
21 Jun 11:23:13 ntpdate[22168]: ntpdate 4.2.4p4@1.1520-o Sun Nov 22 16:14:35 UTC 2009 (1)
transmit(internal-ntp)
receive(internal-ntp)
transmit(internal-ntp)
receive(internal-ntp)
transmit(internal-ntp)
receive(internal-ntp)
transmit(internal-ntp)
receive(internal-ntp)
transmit(internal-ntp)
server internal-ntp, port 123
stratum 3, precision -20, leap 00, trust 000
refid [internal-ntp], delay 0.02632, dispersion 0.00000
transmitted 4, in filter 4
reference time: dcf49c8e.67939494 Wed, Jun 21 2017 11:19:42.404
originate timestamp: dcf49d61.40ad9621 Wed, Jun 21 2017 11:23:13.252
transmit timestamp: dcf49d61.41bf487f Wed, Jun 21 2017 11:23:13.256
filter delay: 0.02632 0.02650 0.02675 0.02650
0.00000 0.00000 0.00000 0.00000
filter offset: -0.00467 -0.00469 -0.00459 -0.00464
0.000000 0.000000 0.000000 0.000000
delay 0.02632, dispersion 0.00000
offset -0.004672
21 Jun 11:23:13 ntpdate[22168]: adjust time server internal-ntp offset -0.004672 sec
Вот трассировка tcpdump сервера, который может синхронизироваться на стороне сервера ntp:
internal-ntp:/var/log# tcpdump host 10.254.250.52
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
11:19:20.105722 IP 10.254.250.52.34851 > internal-ntp.ntp: NTPv4, Client, length 48
11:19:20.105764 IP internal-ntp.ntp > 10.254.250.52.34851: NTPv4, Server, length 48
11:19:20.106471 IP 10.254.250.52.34851 > internal-ntp.ntp: NTPv4, Client, length 48
11:19:20.106499 IP internal-ntp.ntp > 10.254.250.52.34851: NTPv4, Server, length 48
11:19:20.107120 IP 10.254.250.52.34851 > internal-ntp.ntp: NTPv4, Client, length 48
11:19:20.107163 IP internal-ntp.ntp > 10.254.250.52.34851: NTPv4, Server, length 48
11:19:20.107969 IP 10.254.250.52.34851 > internal-ntp.ntp: NTPv4, Client, length 48
11:19:20.108000 IP internal-ntp.ntp > 10.254.250.52.34851: NTPv4, Server, length 48
Вот отладка ntpdate сервера, который не может синхронизироваться:
host-10.254.250.51:~# ntpdate -u -d internal-ntp
21 Jun 11:21:42 ntpdate[6194]: ntpdate 4.2.4p4@1.1520-o Sun Nov 22 16:14:35 UTC 2009 (1)
transmit(internal-ntp)
transmit(internal-ntp)
transmit(internal-ntp)
transmit(internal-ntp)
transmit(internal-ntp)
internal-ntp: Server dropped: no data
server internal-ntp, port 123
stratum 0, precision 0, leap 00, trust 000
refid [internal-ntp], delay 0.00000, dispersion 64.00000
transmitted 4, in filter 4
reference time: 00000000.00000000 Thu, Feb 7 2036 10:28:16.000
originate timestamp: 00000000.00000000 Thu, Feb 7 2036 10:28:16.000
transmit timestamp: dcf49d09.f28900c5 Wed, Jun 21 2017 11:21:45.947
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
21 Jun 11:21:46 ntpdate[6194]: no server suitable for synchronization found
Вот трассировка tcpdump сервера, который не может синхронизироваться на стороне сервера ntp:
internal-ntp:/var/log# tcpdump host 10.254.250.51
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
11:19:40.896719 IP 10.254.250.51.59008 > internal-ntp.ntp: NTPv4, Client, length 48
11:19:40.896763 IP internal-ntp.ntp > 10.254.250.51.59008: NTPv4, Server, length 48
11:19:41.896762 IP 10.254.250.51.59008 > internal-ntp.ntp: NTPv4, Client, length 48
11:19:41.896804 IP internal-ntp.ntp > 10.254.250.51.59008: NTPv4, Server, length 48
11:19:42.896556 IP 10.254.250.51.59008 > internal-ntp.ntp: NTPv4, Client, length 48
11:19:42.896597 IP internal-ntp.ntp > 10.254.250.51.59008: NTPv4, Server, length 48
11:19:43.896851 IP 10.254.250.51.59008 > internal-ntp.ntp: NTPv4, Client, length 48
11:19:43.896891 IP internal-ntp.ntp > 10.254.250.51.59008: NTPv4, Server, length 48
Клиент NTP находится на Debian 5.0.10, а сервер NTP находится на Debian 5.0.8
Конфигурация клиентов NTP:
driftfile /var/lib/ntp/ntp.drift
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
server internal-ntp iburst dynamic
restrict -4 default kod notrap nomodify nopeer noquery
restrict -6 default kod notrap nomodify nopeer noquery
restrict 127.0.0.1
restrict ::1
Конфигурация NTP-сервера на internal-ntp:
driftfile /var/lib/ntp/ntp.drift
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
server 0.debian.pool.ntp.org iburst dynamic
server 1.debian.pool.ntp.org iburst dynamic
server 2.debian.pool.ntp.org iburst dynamic
server 3.debian.pool.ntp.org iburst dynamic
restrict -4 default kod notrap nomodify nopeer noquery
restrict -6 default kod notrap nomodify nopeer noquery
restrict 127.0.0.1
restrict ::1
restrict 10.0.0.0 mask 255.0.0.0 nomodify notrap
Неработающий клиент NTP не получает пакет от сервера, это выглядит как асимметричная маршрутизация между клиентом и сервером.
Эта дата NTP на рабочем клиенте ...
host-10.254.250.52:~# ntpdate -u internal-ntp
21 Jun 14:49:31 ntpdate[7747]: adjust time server internal-ntp offset 0.001020 sec
... Дайте эту трассировку tcpdump на стороне клиента:
host-10.254.250.52:~# tcpdump port 123 and host internal-ntp
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
15:33:43.620356 IP 10.254.250.52.35247 > internal-ntp.ntp: NTPv4, Client, length 48
15:33:43.621062 IP internal-ntp.ntp > 10.254.250.52.35247: NTPv4, Server, length 48
15:33:43.621086 IP 10.254.250.52.35247 > internal-ntp.ntp: NTPv4, Client, length 48
15:33:43.621549 IP internal-ntp.ntp > 10.254.250.52.35247: NTPv4, Server, length 48
15:33:43.621563 IP 10.254.250.52.35247 > internal-ntp.ntp: NTPv4, Client, length 48
15:33:43.622282 IP internal-ntp.ntp > 10.254.250.52.35247: NTPv4, Server, length 48
15:33:43.622294 IP 10.254.250.52.35247 > internal-ntp.ntp: NTPv4, Client, length 48
15:33:43.623012 IP internal-ntp.ntp > 10.254.250.52.35247: NTPv4, Server, length 48
Эта дата NTP на неработающем клиенте ...
host-10.254.250.51:~# ntpdate -u internal-ntp
21 Jun 14:51:24 ntpdate[11773]: no server suitable for synchronization found
... Дайте эту трассировку tcpdump на стороне клиента:
host-10.254.250.51:~# tcpdump dst port 123 and host internal-ntp
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes
14:51:20.334130 IP 10.254.250.51.43811 > internal-ntp.ntp: NTPv4, Client, length 48
14:51:21.334171 IP 10.254.250.51.43811 > internal-ntp.ntp: NTPv4, Client, length 48
14:51:22.334118 IP 10.254.250.51.43811 > internal-ntp.ntp: NTPv4, Client, length 48
14:51:23.334119 IP 10.254.250.51.43811 > internal-ntp.ntp: NTPv4, Client, length 48