网络工程 - Cisco NTP 服务器不响应查询 - 吾爱随笔录

我在层次结构中配置了一个 NTP。在为 Cisco 设备提供时间方面 100% 可靠。在我们的一个站点中，我们允许摄像机、服务器和工作站使用我们的 Catalyst 4500 作为它们的时间源。接入层交换机从4500s拉取时间没有问题。然而，摄像机和服务器出现故障。服务器可能是用户在配置 Windows 时间服务时出错。4500s 上的调试确实显示 NTP 进程收到来自摄像头的请求，但 NTP 进程没有响应。我在核心上的 NTP 配置是：

access-list 23 permit 10.1X.2X.1
access-list 24 permit 10.1X.0.0 0.0.255.255 log
access-list 24 permit 10.2X.0.0 0.0.255.255 log
access-list 24 deny   any log

ntp logging
ntp authentication-key 30 md5 XXXX 7
ntp authenticate
ntp trusted-key 3X
ntp source Vlan1
ntp access-group peer 23
ntp access-group serve 24
ntp update-calendar
ntp server 10.1X.2X.1 key 30

相机请求（导致没有回复）

Feb 26 13:20:34.327 pst: NTP recv pkt on v4 socket, pak = 0x83195238.
Feb 26 13:20:34.327 pst: NTP message received from 10.2X.0.215 on interface 'Vlan1' (10.X.X.2):
Feb 26 13:20:34.327 pst: 
 NTP Header:
   Leap = 11, Version = 4, Mode = 3,
   Stratum = 0,
   Poll Interval = 4,
   Precision = -6,
   Root Delay = 1.0,
   Root Dispersion = 1.0,
   refid = 0.0.0.0,
   Last update reftime = 0.0,
   Originated time = 0.0,
   Received time = 0.0,
   Transmit time = 3602438434.1847076455.
 Hexadecimal equivalent (length = 48):
   0000: E3 00 04 FA 00 01 00 00
   0008: 00 01 00 00 00 00 00 00
   0010: 00 00 00 00 00 00 00 00
   0018: 00 00 00 00 00 00 00 00
   0020: 00 00 00 00 00 00 00 00
   0028: D6 B8 D9 22 6E 18 26 67

Cat 4500 正在运行 NTPv4

Switch#show ntp associations detail 
10.1X.2X.1 configured, ipv4, authenticated, our_master, sane, valid, stratum 3 
ref ID 10.X.X.X, time D6BB4F9D.6151EB70 (10:10:37.380 pst Fri Feb 28 2014)
our mode client, peer mode server, our poll intvl 1024, peer poll intvl 1024
root delay 61.55 msec, root disp 38.98, reach 377, sync dist 87.17
delay 1.78 msec, offset 1.7177 msec, dispersion 1.14, jitter 1.45 msec
precision 2**24, version 4
assoc id 13634, assoc name 10.1X.2X.1
assoc in packets 7068, assoc out packets 7069, assoc error packets 0
org time 00000000.00000000 (16:00:00.000 pst Wed Dec 31 1899)
rec time D6BB5203.C83AE4D7 (10:20:51.782 pst Fri Feb 28 2014)
xmt time D6BB5203.C83AE4D7 (10:20:51.782 pst Fri Feb 28 2014)
filtdelay =     4.85    4.86    3.85    3.83    3.85    1.83    3.83    1.78
filtoffset =   -0.30   -0.32    0.22    0.62    0.38    1.88    0.57    1.71
filterror =     0.97    1.00    1.03    1.06    1.09    1.12    1.15    1.18
minpoll = 6, maxpoll = 10