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NTPサーバープールとの同期中のchrony 3.2の問題

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NTPサーバープールとの同期中のchrony 3.2の問題

同様の問題がありますChrony 3.1はntpサーバーとの同期を拒否します。

想像する：

SLES15 SP2を使用して新しくインストールされたサーバーはchrony 3.2を実行しています。公式のntpd 4.2.8p15を実行する2つのNTPサーバープール（両方ともイントラネット）を構成しました。

質問：

Chronyはプールからサーバーを「プルしますが」サーバーから応答を受け取らないので、その理由を知りたいです。 chrony、ntpd、または私の設定に問題がありますか？

デバッグ：

（私はNTPパケットのデコードを改善するためにハックされたバージョンのtcpdumpを使用しています。）ntpdからの要求は次のとおりです（実際にはリモートで監視されるエニーキャスト要求です）。

10:22:29.373395 IP (tos 0xb8, ttl 4, id 21390, offset 0, flags [DF], proto UDP (17), length 100)
    172.20.16.13.123 > 239.192.123.21.123: [udp sum ok] NTP leap indicator=0 (Nominal), Version=4, Mode=3 (Client), length=72
    Stratum 2 (secondary reference), poll 6 (64s), precision -24
    Root Delay: 0.000106, Root dispersion: 0.004196, Reference-ID: 0xac140219
    Reference Timestamp:  3808714798.372973455 (2020-09-10T08:19:58.372973)
    Originator Timestamp: 0.000000000
    Receive Timestamp:    0.000000000
    Transmit Timestamp:   3808714949.372178320 (2020-09-10T08:22:29.372178)
    MAC: Key ID: 421, SHA1-Digest=48d73ad9 5b1d2401 9a8d3c02 91b849cb 28400475

これと比較して、chrony（ローカルモニタリング）のクエリは次のとおりです。

08:52:33.338684 IP (tos 0x0, ttl 64, id 4141, offset 0, flags [DF], proto UDP (17), length 76)
    h31.51625 > h03.ntp: [bad udp cksum 0x7894 -> 0xea6e!] NTPv4, length 48
        Client, Leap indicator:  (0), Stratum 0 (unspecified), poll 10 (1024s), precision 32
        Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: (unspec)
          Reference Timestamp:  0.000000000
          Originator Timestamp: 0.000000000
          Receive Timestamp:    0.000000000
          Transmit Timestamp:   502153526.517788040 (2052/01/06 06:33:42)
            Originator - Receive Timestamp:  0.000000000
            Originator - Transmit Timestamp: 502153526.517788040 (2052/01/06 06:33:42)

10:12:22.173989 IP (tos 0x0, ttl 64, id 58250, offset 0, flags [DF], proto UDP (17), length 76)
    h31.39573 > nm1.ntp: [bad udp cksum 0x6a92 -> 0x02d5!] NTP leap indicator=0 (Nominal), Version=4, Mode=3 (Client), length=48
    Stratum 0 (unspecified), poll 9 (512s), precision 32
    Root Delay: 0.000000, Root dispersion: 0.000000, Reference-ID: 00000000
    Reference Timestamp:  0.000000000
    Originator Timestamp: 0.000000000
    Receive Timestamp:    0.000000000
    Transmit Timestamp:   1885145870.079837521 (2095-11-03T02:06:06.079838)

少なくともタイムスタンプを送信するのは奇妙に見え、他のフィールドが有効かどうかわかりません。

問題はchronyの要求パケットである可能性がありますが、サーバーの一部のフィルタリングによって要求が無視される可能性があります。パケットが1つ以上のプールサーバーに到達することを確認しましたが、応答がありません。

実際、プールの外側の1つのサーバー（最後に表示されたパケットのサーバー）は、奇数イニシエータータイムスタンプを維持しながら、次のように応答します。

10:12:22.174191 IP (tos 0xb8, ttl 63, id 30184, offset 0, flags [DF], proto UDP (17), length 76)
    nm1.ntp > h31.39573: [udp sum ok] NTP leap indicator=0 (Nominal), Version=4, Mode=4 (Server), length=48
    Stratum 3 (secondary reference), poll 9 (512s), precision -23
    Root Delay: 0.000518, Root dispersion: 0.025527, Reference-ID: 0xac141002
    Reference Timestamp:  3808714309.712800696 (2020-09-10T08:11:49.712801)
    Originator Timestamp: 1885145870.079837521 (2095-11-03T02:06:06.079838)
    Receive Timestamp:    3808714342.174128206 (2020-09-10T08:12:22.174128)
    Transmit Timestamp:   3808714342.174187417 (2020-09-10T08:12:22.174187)

追加のデバッグ情報

# chronyc -n
chrony version 3.2
Copyright (C) 1997-2003, 2007, 2009-2017 Richard P. Curnow and others
chrony comes with ABSOLUTELY NO WARRANTY.  This is free software, and
you are welcome to redistribute it under certain conditions.  See the
GNU General Public License version 2 for details.

chronyc> tracking
Reference ID    : 00000000 ()
Stratum         : 0
Ref time (UTC)  : Thu Jan 01 00:00:00 1970
System time     : 0.000000009 seconds slow of NTP time
Last offset     : +0.000000000 seconds
RMS offset      : 0.000000000 seconds
Frequency       : 86.905 ppm slow
Residual freq   : +0.000 ppm
Skew            : 0.000 ppm
Root delay      : 1.000000000 seconds
Root dispersion : 1.000000000 seconds
Update interval : 0.0 seconds
Leap status     : Not synchronised
chronyc> sources
210 Number of sources = 8
MS Name/IP address         Stratum Poll Reach LastRx Last sample
===============================================================================
^? 172.20.16.3                   0  10     0     -     +0ns[   +0ns] +/-    0ns
^? 172.20.16.1                   0  10     0     -     +0ns[   +0ns] +/-    0ns
^? 172.20.16.13                  0  10     0     -     +0ns[   +0ns] +/-    0ns
^? 172.20.16.14                  0  10     0     -     +0ns[   +0ns] +/-    0ns
^? 172.20.16.5                   0  10     0     -     +0ns[   +0ns] +/-    0ns
^? 172.20.16.12                  0  10     0     -     +0ns[   +0ns] +/-    0ns
^? 172.20.16.11                  0  10     0     -     +0ns[   +0ns] +/-    0ns
^- 172.20.2.1                    3  10   377   667   +16.2s[ +16.2s] +/-   36ms
chronyc> sourcestats
210 Number of sources = 8
Name/IP Address            NP  NR  Span  Frequency  Freq Skew  Offset  Std Dev
==============================================================================
172.20.16.3                 0   0     0     +0.000   2000.000     +0ns  4000ms
172.20.16.1                 0   0     0     +0.000   2000.000     +0ns  4000ms
172.20.16.13                0   0     0     +0.000   2000.000     +0ns  4000ms
172.20.16.14                0   0     0     +0.000   2000.000     +0ns  4000ms
172.20.16.5                 0   0     0     +0.000   2000.000     +0ns  4000ms
172.20.16.12                0   0     0     +0.000   2000.000     +0ns  4000ms
172.20.16.11                0   0     0     +0.000   2000.000     +0ns  4000ms
172.20.2.1                 22  10  232m     -0.650      0.003   +16.2s    17us
chronyc> activity
200 OK
8 sources online
0 sources offline
0 sources doing burst (return to online)
0 sources doing burst (return to offline)
0 sources with unknown address
chronyc> ntpdata

Remote address  : [UNSPEC] (00000000)
Remote port     : 0
Local address   : [UNSPEC] (00000000)
Leap status     : Normal
Version         : 0
Mode            : Invalid
Stratum         : 0
Poll interval   : 0 (1 seconds)
Precision       : 0 (1.000000000 seconds)
Root delay      : 0.000000 seconds
Root dispersion : 0.000000 seconds
Reference ID    : 00000000 ()
Reference time  : Thu Jan 01 00:00:00 1970
Offset          : +0.000000000 seconds
Peer delay      : 0.000000000 seconds
Peer dispersion : 0.000000000 seconds
Response time   : 0.000000000 seconds
Jitter asymmetry: +0.00
NTP tests       : 000 000 0000
Interleaved     : No
Authenticated   : No
TX timestamping : Invalid
RX timestamping : Invalid
Total TX        : 672
Total RX        : 0
Total valid RX  : 0

Remote address  : [UNSPEC] (00000000)
Remote port     : 0
Local address   : [UNSPEC] (00000000)
Leap status     : Normal
Version         : 0
Mode            : Invalid
Stratum         : 0
Poll interval   : 0 (1 seconds)
Precision       : 0 (1.000000000 seconds)
Root delay      : 0.000000 seconds
Root dispersion : 0.000000 seconds
Reference ID    : 00000000 ()
Reference time  : Thu Jan 01 00:00:00 1970
Offset          : +0.000000000 seconds
Peer delay      : 0.000000000 seconds
Peer dispersion : 0.000000000 seconds
Response time   : 0.000000000 seconds
Jitter asymmetry: +0.00
NTP tests       : 000 000 0000
Interleaved     : No
Authenticated   : No
TX timestamping : Invalid
RX timestamping : Invalid
Total TX        : 672
Total RX        : 0
Total valid RX  : 0

Remote address  : [UNSPEC] (00000000)
Remote port     : 0
Local address   : [UNSPEC] (00000000)
Leap status     : Normal
Version         : 0
Mode            : Invalid
Stratum         : 0
Poll interval   : 0 (1 seconds)
Precision       : 0 (1.000000000 seconds)
Root delay      : 0.000000 seconds
Root dispersion : 0.000000 seconds
Reference ID    : 00000000 ()
Reference time  : Thu Jan 01 00:00:00 1970
Offset          : +0.000000000 seconds
Peer delay      : 0.000000000 seconds
Peer dispersion : 0.000000000 seconds
Response time   : 0.000000000 seconds
Jitter asymmetry: +0.00
NTP tests       : 000 000 0000
Interleaved     : No
Authenticated   : No
TX timestamping : Invalid
RX timestamping : Invalid
Total TX        : 672
Total RX        : 0
Total valid RX  : 0

Remote address  : [UNSPEC] (00000000)
Remote port     : 0
Local address   : [UNSPEC] (00000000)
Leap status     : Normal
Version         : 0
Mode            : Invalid
Stratum         : 0
Poll interval   : 0 (1 seconds)
Precision       : 0 (1.000000000 seconds)
Root delay      : 0.000000 seconds
Root dispersion : 0.000000 seconds
Reference ID    : 00000000 ()
Reference time  : Thu Jan 01 00:00:00 1970
Offset          : +0.000000000 seconds
Peer delay      : 0.000000000 seconds
Peer dispersion : 0.000000000 seconds
Response time   : 0.000000000 seconds
Jitter asymmetry: +0.00
NTP tests       : 000 000 0000
Interleaved     : No
Authenticated   : No
TX timestamping : Invalid
RX timestamping : Invalid
Total TX        : 672
Total RX        : 0
Total valid RX  : 0

Remote address  : [UNSPEC] (00000000)
Remote port     : 0
Local address   : [UNSPEC] (00000000)
Leap status     : Normal
Version         : 0
Mode            : Invalid
Stratum         : 0
Poll interval   : 0 (1 seconds)
Precision       : 0 (1.000000000 seconds)
Root delay      : 0.000000 seconds
Root dispersion : 0.000000 seconds
Reference ID    : 00000000 ()
Reference time  : Thu Jan 01 00:00:00 1970
Offset          : +0.000000000 seconds
Peer delay      : 0.000000000 seconds
Peer dispersion : 0.000000000 seconds
Response time   : 0.000000000 seconds
Jitter asymmetry: +0.00
NTP tests       : 000 000 0000
Interleaved     : No
Authenticated   : No
TX timestamping : Invalid
RX timestamping : Invalid
Total TX        : 672
Total RX        : 0
Total valid RX  : 0

Remote address  : [UNSPEC] (00000000)
Remote port     : 0
Local address   : [UNSPEC] (00000000)
Leap status     : Normal
Version         : 0
Mode            : Invalid
Stratum         : 0
Poll interval   : 0 (1 seconds)
Precision       : 0 (1.000000000 seconds)
Root delay      : 0.000000 seconds
Root dispersion : 0.000000 seconds
Reference ID    : 00000000 ()
Reference time  : Thu Jan 01 00:00:00 1970
Offset          : +0.000000000 seconds
Peer delay      : 0.000000000 seconds
Peer dispersion : 0.000000000 seconds
Response time   : 0.000000000 seconds
Jitter asymmetry: +0.00
NTP tests       : 000 000 0000
Interleaved     : No
Authenticated   : No
TX timestamping : Invalid
RX timestamping : Invalid
Total TX        : 672
Total RX        : 0
Total valid RX  : 0

Remote address  : [UNSPEC] (00000000)
Remote port     : 0
Local address   : [UNSPEC] (00000000)
Leap status     : Normal
Version         : 0
Mode            : Invalid
Stratum         : 0
Poll interval   : 0 (1 seconds)
Precision       : 0 (1.000000000 seconds)
Root delay      : 0.000000 seconds
Root dispersion : 0.000000 seconds
Reference ID    : 00000000 ()
Reference time  : Thu Jan 01 00:00:00 1970
Offset          : +0.000000000 seconds
Peer delay      : 0.000000000 seconds
Peer dispersion : 0.000000000 seconds
Response time   : 0.000000000 seconds
Jitter asymmetry: +0.00
NTP tests       : 000 000 0000
Interleaved     : No
Authenticated   : No
TX timestamping : Invalid
RX timestamping : Invalid
Total TX        : 672
Total RX        : 0
Total valid RX  : 0

Remote address  : 172.20.2.1 (AC140201)
Remote port     : 123
Local address   : 172.20.16.31 (AC14101F)
Leap status     : Normal
Version         : 4
Mode            : Server
Stratum         : 3
Poll interval   : 10 (1024 seconds)
Precision       : -23 (0.000000119 seconds)
Root delay      : 0.000534 seconds
Root dispersion : 0.036041 seconds
Reference ID    : AC141002 ()
Reference time  : Thu Oct 08 08:20:28 2020
Offset          : -16.152969360 seconds
Peer delay      : 0.000214426 seconds
Peer dispersion : 0.000000195 seconds
Response time   : 0.000017658 seconds
Jitter asymmetry: +0.23
NTP tests       : 111 111 1111
Interleaved     : No
Authenticated   : No
TX timestamping : Daemon
RX timestamping : Daemon
Total TX        : 1969
Total RX        : 1969
Total valid RX  : 1969
chronyc> clients
Hostname                      NTP   Drop Int IntL Last     Cmd   Drop Int  Last
===============================================================================
chronyc> serverstats
NTP packets received       : 0
NTP packets dropped        : 0
Command packets received   : 81
Command packets dropped    : 0
Client log records dropped : 0
chronyc> rtcdata
513 RTC driver not running
chronyc> quit
# journalctl -b SYSLOG_IDENTIFIER=chronyd
-- Logs begin at Wed 2020-09-30 13:32:17 CEST, end at Thu 2020-10-08 11:27:08 CEST. --
Sep 30 13:33:04 h31 chronyd[3522]: chronyd version 3.2 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP -SCFILTER +>
Sep 30 13:33:04 h31 chronyd[3522]: Enabled HW timestamping (TX only) on em3
Sep 30 13:33:04 h31 chronyd[3522]: Enabled HW timestamping (TX only) on em4
Sep 30 13:33:04 h31 chronyd[3522]: Frequency -86.905 +/- 0.107 ppm read from /var/lib/chrony/drift

答え1

mask私は問題を解決し、実際には1つのサーバーを除くすべてのサーバーがNTP時間クエリに応答しないようにするディレクティブの悪い問題でした。また、私はすでにそれを設定しています。ntpdrestrictminsources 3/etc/chrony.conf

この問題の興味深い点は、chronydこれを処理することです（」追加のデバッグ情報「問題があります）：

  • いいですね。reachisの出力に表示される可能性があるさまざまな問題があります。sources0

  • ntpdata実際にデータがない場合に大量のデータを出力します。私が逃した重要な手がかりTotal RXの1つもゼロでしたTotal valid RX。しかし、ここにはまだいくつかの理由があるかもしれません。

  • serverstats明らかに応答が実際に送信されたので、表示がゼロであることがNTP packets received奇妙に見えます。172.20.2.1

  • activity混乱しているよう8 sources onlineです0 sources offline。応答しないソースを「オンライン」ではなく「オフライン」と見なすべきではありませんか？

これに比べて問題が解決された後の出力は次のとおりです（3つの応答ソースを使用）。

Oct 08 11:29:32 h31 systemd[1]: Starting NTP client/server...
Oct 08 11:29:32 h31 chronyd[18823]: chronyd version 3.2 starting (+CMDMON +NTP +REFCLOCK +RTC +PRIVDROP -SCFILTER >
Oct 08 11:29:32 h31 chronyd[18823]: Enabled HW timestamping (TX only) on em3
Oct 08 11:29:32 h31 chronyd[18823]: Enabled HW timestamping (TX only) on em4
Oct 08 11:29:32 h31 chronyd[18823]: Frequency -86.905 +/- 0.107 ppm read from /var/lib/chrony/drift
Oct 08 11:29:32 h31 systemd[1]: Started NTP client/server.
Oct 09 08:09:43 h31 chronyd[18823]: Selected source 172.20.2.1
Oct 09 08:09:43 h31 chronyd[18823]: System clock wrong by -16.101294 seconds, adjustment started
Oct 09 08:09:27 h31 chronyd[18823]: System clock was stepped by -16.101294 seconds
Oct 09 08:11:36 h31 chronyd[18823]: Selected source 172.20.16.3

chronyc> tracking
Reference ID    : AC141003 (172.20.16.3)
Stratum         : 3
Ref time (UTC)  : Fri Oct 09 06:21:18 2020
System time     : 0.000007615 seconds fast of NTP time
Last offset     : +0.000007168 seconds
RMS offset      : 0.000022300 seconds
Frequency       : 87.841 ppm slow
Residual freq   : +0.002 ppm
Skew            : 0.090 ppm
Root delay      : 0.000269273 seconds
Root dispersion : 0.002195312 seconds
Update interval : 64.6 seconds
Leap status     : Normal
chronyc> sources
210 Number of sources = 9
MS Name/IP address         Stratum Poll Reach LastRx Last sample
===============================================================================
^? 172.20.16.13                  0  10     0     -     +0ns[   +0ns] +/-    0ns
^? 172.20.16.1                   0  10     0     -     +0ns[   +0ns] +/-    0ns
^? 172.20.16.5                   0  10     0     -     +0ns[   +0ns] +/-    0ns
^? 172.20.16.12                  0  10     0     -     +0ns[   +0ns] +/-    0ns
^? 172.20.16.14                  0  10     0     -     +0ns[   +0ns] +/-    0ns
^? 172.20.16.11                  0  10     0     -     +0ns[   +0ns] +/-    0ns
^- 172.20.2.1                    3   9   377   239    +15us[  +27us] +/-   27ms
^- 172.20.16.2                   2   8   377    65   +208us[ +215us] +/- 8147us
^* 172.20.16.3                   2   6   377    64    +27us[  +34us] +/- 4417us
chronyc> sourcestats
210 Number of sources = 9
Name/IP Address            NP  NR  Span  Frequency  Freq Skew  Offset  Std Dev
==============================================================================
172.20.16.13                0   0     0     +0.000   2000.000     +0ns  4000ms
172.20.16.1                 0   0     0     +0.000   2000.000     +0ns  4000ms
172.20.16.5                 0   0     0     +0.000   2000.000     +0ns  4000ms
172.20.16.12                0   0     0     +0.000   2000.000     +0ns  4000ms
172.20.16.14                0   0     0     +0.000   2000.000     +0ns  4000ms
172.20.16.11                0   0     0     +0.000   2000.000     +0ns  4000ms
172.20.2.1                  7   5   51m     +0.254      0.070   +105us    23us
172.20.16.2                 6   3   21m     +0.219      0.218   +227us    27us
172.20.16.3                15   7   907     +0.002      0.074    +52ns    19us
chronyc> activity
200 OK
9 sources online
0 sources offline
0 sources doing burst (return to online)
0 sources doing burst (return to offline)
0 sources with unknown address
chronyc> ntpdata
...
Remote address  : 172.20.2.1 (AC140201)
Remote port     : 123
Local address   : 172.20.16.31 (AC14101F)
Leap status     : Normal
Version         : 4
Mode            : Server
Stratum         : 3
Poll interval   : 9 (512 seconds)
Precision       : -23 (0.000000119 seconds)
Root delay      : 0.000366 seconds
Root dispersion : 0.026947 seconds
Reference ID    : AC14100E ()
Reference time  : Fri Oct 09 06:11:14 2020
Offset          : -0.000026963 seconds
Peer delay      : 0.000219559 seconds
Peer dispersion : 0.000000190 seconds
Response time   : 0.000020624 seconds
Jitter asymmetry: +0.20
NTP tests       : 111 111 1111
Interleaved     : No
Authenticated   : No
TX timestamping : Daemon
RX timestamping : Daemon
Total TX        : 297
Total RX        : 296
Total valid RX  : 296

Remote address  : 172.20.16.2 (AC141002)
Remote port     : 123
Local address   : 172.20.16.31 (AC14101F)
Leap status     : Normal
Version         : 4
Mode            : Server
Stratum         : 2
Poll interval   : 8 (256 seconds)
Precision       : -23 (0.000000119 seconds)
Root delay      : 0.000305 seconds
Root dispersion : 0.007904 seconds
Reference ID    : AC140219 ()
Reference time  : Fri Oct 09 06:14:48 2020
Offset          : -0.000215189 seconds
Peer delay      : 0.000180311 seconds
Peer dispersion : 0.000000190 seconds
Response time   : 0.000057180 seconds
Jitter asymmetry: +0.50
NTP tests       : 111 111 1111
Interleaved     : No
Authenticated   : Yes
TX timestamping : Daemon
RX timestamping : Daemon
Total TX        : 466
Total RX        : 453
Total valid RX  : 453

Remote address  : 172.20.16.3 (AC141003)
Remote port     : 123
Local address   : 172.20.16.31 (AC14101F)
Leap status     : Normal
Version         : 4
Mode            : Server
Stratum         : 2
Poll interval   : 6 (64 seconds)
Precision       : -24 (0.000000060 seconds)
Root delay      : 0.000168 seconds
Root dispersion : 0.006165 seconds
Reference ID    : AC140219 ()
Reference time  : Fri Oct 09 06:18:14 2020
Offset          : -0.000028130 seconds
Peer delay      : 0.000198109 seconds
Peer dispersion : 0.000000131 seconds
Response time   : 0.000038736 seconds
Jitter asymmetry: +0.00
NTP tests       : 111 111 1111
Interleaved     : No
Authenticated   : No
TX timestamping : Daemon
RX timestamping : Daemon
Total TX        : 16
Total RX        : 16
Total valid RX  : 16
chronyc> serverstats
NTP packets received       : 0
NTP packets dropped        : 0
Command packets received   : 353
Command packets dropped    : 0
Client log records dropped : 0
chronyc> rtcdata
513 RTC driver not running

chronydまたはにバグがあるようですchronyc。

関連情報