Solved: Re: Clock not syncing with NTP server - Page 2

mjhagen · ‎07-16-2008

I am having issues with 3600 and 7200 routers not sysncing with NTP server. My NTP server is working fine as I have other devices syncing to it. The 3600 and 7200 routers can sync to public NTP servers on the internet but cannot sync to my internal NTP server. The routers do have access to the NTP server because they and ping and traceroute to it.

jayadev13 · ‎04-03-2019

I'm having the same issue where cisco 2921 router is having an issue pulling time from NTP server (Windows server 2008 r2)

The server is reachable and the interesting thing is its able to sync if i enable SNTP but unable to sync time with NTP

The details are as below:

TBG-WAN-EDGE#sh ip interface brief
Interface IP-Address OK? Method Status Protocol
Embedded-Service-Engine0/0 unassigned YES NVRAM administratively down down
GigabitEthernet0/0 [Public IP] YES NVRAM up up
GigabitEthernet0/1 [Public IP] YES NVRAM up up
GigabitEthernet0/2 unassigned YES NVRAM up up
GigabitEthernet0/2.1 192.168.25.1 YES NVRAM up up
GigabitEthernet0/2.20 192.168.20.1 YES NVRAM up up

NTP Server IP: 192.168.20.5

TBG-WAN-EDGE#show ntp status
Clock is unsynchronized, stratum 16, no reference clock
nominal freq is 250.0000 Hz, actual freq is 250.0001 Hz, precision is 2**19
ntp uptime is 180000 (1/100 of seconds), resolution is 4000
reference time is 00000000.00000000 (19:00:00.000 est Thu Dec 31 1899)
clock offset is 0.0000 msec, root delay is 0.00 msec
root dispersion is 0.76 msec, peer dispersion is 0.00 msec
loopfilter state is 'FSET' (Drift set from file), drift is -0.000000492 s/s
system poll interval is 64, never updated.

Apr 3 16:50:56.272: NTP message sent to 192.168.20.5, from interface 'GigabitEthernet0/2.20' (192.168.20.1).
Apr 3 16:50:56.272: NTP message received from 192.168.20.5 on interface 'GigabitEthernet0/2.20' (192.168.20.1).
Apr 3 16:50:56.272: NTP Core(DEBUG): ntp_receive: message received
Apr 3 16:50:56.272: NTP Core(DEBUG): ntp_receive: peer is 0x2431FD5C, next action is 1.
Apr 3 16:50:56.272: NTP Core(INFO): 0.0.0.0 C0EC 0C clock_step
TBG-WAN-EDGE#
Apr 3 16:51:56.072: NTP message received from 192.168.20.14 on interface 'GigabitEthernet0/1' (173.167.48.249).
Apr 3 16:51:56.072: NTP Core(DEBUG): ntp_receive: message received
Apr 3 16:51:56.072: NTP Core(NOTICE): ntp_receive: dropping message: MODE_CONTROL ratecontrol.

TBG-WAN-EDGE#show ntp associations

address ref clock st when poll reach delay offset disp
~192.168.20.5 .LOCL. 1 25 64 377 0.847 -133.50 16.549
* sys.peer, # selected, + candidate, - outlyer, x falseticker, ~ configured

TBG-WAN-EDGE#sh ntp associations detail
192.168.20.5 configured, ipv4, insane, invalid, stratum 1
ref ID .LOCL., time E04F6505.9F250CFF (11:59:49.621 est Wed Apr 3 2019)
our mode client, peer mode server, our poll intvl 64, peer poll intvl 64
root delay 0.00 msec, root disp 10046.08, reach 1, sync dist 10249.94
delay 0.86 msec, offset -0.9529 msec, dispersion 202.90, jitter 0.52 msec
precision 2**6, version 4
assoc id 50886, assoc name 192.168.20.5
assoc in packets 6, assoc out packets 6, assoc error packets 0
org time 00000000.00000000 (19:00:00.000 est Thu Dec 31 1899)
rec time E04F6F50.0EC2BF2C (12:43:44.057 est Wed Apr 3 2019)
xmt time E04F6F50.0EC2BF2C (12:43:44.057 est Wed Apr 3 2019)
filtdelay = 0.86 0.86 0.91 1.02 0.92 0.96 0.00 0.00
filtoffset = -0.95 -1.10 -1.20 -0.38 -0.44 -0.12 0.00 0.00
filterror = 15.62 15.65 15.68 15.71 15.74 15.77 16000.0 16000.0
minpoll = 6, maxpoll = 10

Please let me know if you can find the issue. Thanks in advance

Georg Pauwen · ‎04-03-2019

Hello,

did you follow the suggestion in the previous post, which was setting the clock manually to something very close to the real time ?

2921#clock set

jayadev13 · ‎04-03-2019

Yes. I did check that and set almost the same time as server. I also disabled and re-enabled ntp. Still no luck. Below is the trace of debug message and the result of "show ntp association detail"

I did the below steps:

router(config)#clock set 23:00:00 03 Apr 2019

router(config)#no ntp

router(config)#ntp server 192.168.20.5 prefer source gigabitEthernet 0/2.20

The debug is as below as soon as i enabled NTP,

Apr 4 04:01:40.687: NTP Core(INFO): keys initilized.
Apr 4 04:01:40.687: NTP Core(NOTICE): proto: precision = usec
Apr 4 04:01:40.687: %NTP : Drift Read : FFFFFFFF.FFFFF7BD
Apr 4 04:01:40.687: NTP Core(DEBUG): drift value read: -0.000000000
Apr 4 04:01:40.687: NTP Core(NOTICE): ntpd PPM
Apr 4 04:01:40.687: NTP: Initialized interface Embedded-Service-Engine0/0
Apr 4 04:01:40.687: NTP: Initialized interface GigabitEthernet0/0
Apr 4 04:01:40.687: NTP: Initialized interface GigabitEthernet0/1
Apr 4 04:01:40.687: NTP: Initialized interface GigabitEthernet0/2
Apr 4 04:01:40.687: NTP: Initialized interface GigabitEthernet0/2.1
Apr 4 04:01:40.687: NTP: Initialized interface GigabitEthernet0/2.20
Apr 4 04:01:40.687: NTP: Initialized interface GigabitEthernet0/2.40
Apr 4 04:01:40.687: NTP: Initialized interface GigabitEthernet0/2.50
Apr 4 04:01:40.687: NTP: Initialized interface Backplane-GigabitEthernet0/3
Apr 4 04:01:40.687: NTP: Initialized interface NVI0
Apr 4 04:01:40.687: NTP: Initialized interface RG-AR-IF-INPUT1
Apr 4 04:01:40.687: NTP: Initialized interface Tunnel1
Apr 4 04:01:40.687: NTP: Initialized interface Tunnel2
Apr 4 04:01:40.687: NTP: Initialized interface VoIP-Null0
Apr 4 04:01:40.691: %PARSER-5-CFGLOG_LOGGEDCMD: User:**** logged command:ntp server 192.168.20.5 prefer source GigabitEthernet0/2.20
Apr 4 04:01:40.691: NTP message sent to 192.168.20.5, from interface 'GigabitEthernet0/2.20' (192.168.20.1).
Apr 4 04:01:40.691: NTP message received from 192.168.20.5 on interface 'GigabitEthernet0/2.20' (192.168.20.1).
Apr 4 04:01:40.691: NTP Core(DEBUG): ntp_receive: message received
Apr 4 04:01:40.691: NTP Core(DEBUG): ntp_receive: peer is 0x2458AB7C, next action is 1.
Apr 4 04:01:40.691: NTP Core(DEBUG): Peer becomes reachable, poll set to 6.

Apr 4 04:01:40.691: NTP Core(INFO): 192.168.20.5 8014 84 reachable
Apr 4 04:01:40.691: NTP Core(INFO): 192.168.20.5 902D 8D popcorn popcorn

Apr 4 04:01:42.691: NTP message sent to 192.168.20.5, from interface 'GigabitEthernet0/2.20' (192.168.20.1).
Apr 4 04:01:42.691: NTP message received from 192.168.20.5 on interface 'GigabitEthernet0/2.20' (192.168.20.1).
Apr 4 04:01:42.691: NTP Core(DEBUG): ntp_receive: message received
Apr 4 04:01:42.691: NTP Core(DEBUG): ntp_receive: peer is 0x2458AB7C, next action is 1.
Apr 4 04:01:42.691: NTP Core(INFO): 0.0.0.0 C01C 0C clock_step

Apr 4 04:01:44.691: NTP message sent to 192.168.20.5, from interface 'GigabitEthernet0/2.20' (192.168.20.1).
Apr 4 04:01:44.691: NTP message received from 192.168.20.5 on interface 'GigabitEthernet0/2.20' (192.168.20.1).
Apr 4 04:01:44.691: NTP Core(DEBUG): ntp_receive: message received
Apr 4 04:01:44.691: NTP Core(DEBUG): ntp_receive: peer is 0x2458AB7C, next action is 1.
Apr 4 04:01:44.691: NTP Core(INFO): 0.0.0.0 C02C 0C clock_step

Apr 4 04:01:46.691: NTP message sent to 192.168.20.5, from interface 'GigabitEthernet0/2.20' (192.168.20.1).
Apr 4 04:01:46.691: NTP message received from 192.168.20.5 on interface 'GigabitEthernet0/2.20' (192.168.20.1).
Apr 4 04:01:46.691: NTP Core(DEBUG): ntp_receive: message received
Apr 4 04:01:46.691: NTP Core(DEBUG): ntp_receive: peer is 0x2458AB7C, next action is 1.
Apr 4 04:01:46.691: NTP Core(INFO): 0.0.0.0 C03C 0C clock_step

Apr 4 04:01:48.691: NTP message sent to 192.168.20.5, from interface 'GigabitEthernet0/2.20' (192.168.20.1).
Apr 4 04:01:48.691: NTP message received from 192.168.20.5 on interface 'GigabitEthernet0/2.20' (192.168.20.1).
Apr 4 04:01:48.691: NTP Core(DEBUG): ntp_receive: message received
Apr 4 04:01:48.691: NTP Core(DEBUG): ntp_receive: peer is 0x2458AB7C, next action is 1.
Apr 4 04:01:48.691: NTP Core(INFO): 0.0.0.0 C04C 0C clock_step
Router#
Apr 4 04:01:50.691: NTP message sent to 192.168.20.5, from interface 'GigabitEthernet0/2.20' (192.168.20.1).
Apr 4 04:01:50.691: NTP message received from 192.168.20.5 on interface 'GigabitEthernet0/2.20' (192.168.20.1).
Apr 4 04:01:50.691: NTP Core(DEBUG): ntp_receive: message received
Apr 4 04:01:50.691: NTP Core(DEBUG): ntp_receive: peer is 0x2458AB7C, next action is 1.
Apr 4 04:01:50.691: NTP Core(INFO): 0.0.0.0 C05C 0C clock_step

Router#show ntp status
Clock is unsynchronized, stratum 16, no reference clock
nominal freq is 250.0000 Hz, actual freq is 250.0001 Hz, precision is 2**19
ntp uptime is 1900 (1/100 of seconds), resolution is 4000
reference time is 00000000.00000000 (19:00:00.000 est Thu Dec 31 1899)
clock offset is 0.0000 msec, root delay is 0.00 msec
root dispersion is 0.11 msec, peer dispersion is 0.00 msec
loopfilter state is 'FSET' (Drift set from file), drift is -0.000000492 s/s
system poll interval is 64, never updated.

Router#show clock
23:02:16.255 est Wed Apr 3 2019

Apr 4 04:02:16.831: NTP message received from 192.168.20.14 on interface 'GigabitEthernet0/2.20' (192.168.20.1).
Apr 4 04:02:16.831: NTP Core(DEBUG): ntp_receive: message received
Apr 4 04:02:16.831: NTP Core(NOTICE): ntp_receive: dropping message: MODE_CONTROL ratecontrol.

Router#show ntp associations detail
192.168.20.5 configured, ipv4, insane, invalid, stratum 1
ref ID .LOCL., time E04F6505.9F632A71 (11:59:49.622 est Wed Apr 3 2019)
our mode client, peer mode server, our poll intvl 64, peer poll intvl 64
root delay 0.00 msec, root disp 10433.99, reach 3, sync dist 10514.90
delay 1.18 msec, offset -3629643.9705 msec, dispersion 78.44, jitter 1.15 msec
precision 2**6, version 4
assoc id 6176, assoc name 192.168.20.5
assoc in packets 7, assoc out packets 7, assoc error packets 0
org time 00000000.00000000 (19:00:00.000 est Thu Dec 31 1899)
rec time E04FF23B.0C718075 (22:02:19.048 est Wed Apr 3 2019)
xmt time E04FF23B.0C718075 (22:02:19.048 est Wed Apr 3 2019)
filtdelay = 1.18 0.96 0.92 1.02 0.87 0.92 1.26 0.00
filtoffset = -362964 -362964 -362964 -362964 -362964 -362964 -362964 0.00
filterror = 15.62 16.49 16.52 16.55 16.58 16.61 16.64 16000.0
minpoll = 6, maxpoll = 10

Georg Pauwen · ‎04-04-2019

Hello,

what if you use:

ntp server 0.pool.ntp.org

instead of the Windows 2008 machine ?

jayadev13 · ‎04-04-2019

Yes. I can do that with proper approvals but I was curious to know why it
wasn't working. The current NTP server (Windows server 2008r2 192.168.20.5)
is running a local clock and according to theory it should serve its own
time to NTP clients right?

Georg Pauwen · ‎04-04-2019

Hello,

how did you set up the Windows 2008 server for NTP ? Like described in the document below ?

https://support.microsoft.com/en-us/help/816042/how-to-configure-an-authoritative-time-server-in-windows-server

jayadev13 · ‎04-04-2019

I used the below link to configure the server,

https://bchavez.bitarmory.com/how-to-setup-a-windows-2008-r2-sntp-ntp-server/#

I think it contains almost all the main steps to enable NTP. that is mentioned in the link that you posted.

Right now, my edge router's ACL is blocking the incoming NTP traffic. So, can we modify the ACLs to allow only the Windows server 2008 R2 to sync time with external source and point all other network devices (including the edge router) to pull time from this server ?

What do you recommend ?

Georg Pauwen · ‎04-05-2019

Hello,

not sure where exactly in your topology the router is, but any ACL needs to allow UDP port 123 for NTP to work...

jayadev13 · ‎04-03-2019

Does this have anything to do with the issue ?

service timestamps debug datetime msec
service timestamps log datetime msec

clock timezone est -5 0

jijain · ‎06-29-2021

I am facing the same issue..Can you let me know how the problem got solved ???