NTP is not Sync

[nexus13213]

Hi,

I have a log fault, which says that my NTP doesn't sync.
has anyone ever experienced this?

thanks

[Nik Noltenius]

Hi,

I have seen this temporarily after firmware upgrades but the fault always got resolved automatically after some time.

Did it work before or is this a fresh configuration?

Are you sure your NTP is reachable via OBM? Maybe a firewall blocking NTP traffic?

Regards,

Nik

[nexus13213]

Hi,

it's been more than a week after I upgraded, and the error is still there.
is there anything I can do to verify or to troubleshoot this issue?

and besides upgrading, I also imported configuration from ftp.

thanks 

[Alexander09]

Hi,

Perform on a leaf switch go into nexus shell (type vsh when logged on) and do a <show ntp statistics> and <show ntp peer-status>?

On the APIC controller go into shell mode (type bash and enter) and do <ntpq -p>, this should list your ntp peers with the status and or an indication what the issue might be.

What I have seen is that the problem might be that the ntp server you configured is unable to sync it's time (upstream ntp).

cheers

Alexander

[nexus13213]

Hi Alex,

here the output,

Leaf-201# show ntp statistics peer ipaddr 10.2.35.150
remote host:          10.2.35.150  
local interface:      Unresolved
time last received:   29s
time until next send: 35s
reachability change:  73032s
packets sent:         1122
packets received:     0
bad authentication:   0
bogus origin:         0
duplicate:            1
bad dispersion:       1122
bad reference time:   0
candidate order:      0
Leaf-201# 
Leaf-201# show ntp statistics peer ipaddr 10.2.35.172
remote host:          10.2.35.172  
local interface:      Unresolved
time last received:   6s
time until next send: 10s
reachability change:  73030s
packets sent:         4565
packets received:     4565
bad authentication:   0
bogus origin:         0
duplicate:            3
bad dispersion:       0
bad reference time:   0
candidate order:      0
Leaf-201# show ntp peer-status 
Total peers : 2
* - selected for sync, + -  peer mode(active), 
- - peer mode(passive), = - polled in client mode 
    remote                               local                 st   poll   reach delay   vrf
--------------------------------------------------------------------------------------
=10.2.35.172                              0.0.0.0                 1   16     377   0.00053 management
=10.2.35.150                              0.0.0.0                16   64       0   0.00000 management

admin@APIC-01:~> ntpq -p
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
 10.2.35.150     .INIT.          16 u   35   64    0    0.000    0.000   0.000
 10.2.35.172     .LOCL.           1 u   15   16  377    0.344  10358.7   0.286
admin@APIC-01:~> 

so this isn't a problem from the apic? but from the ntp server itself which doesn't sync?

Thanks

[Alexander09]

Hi,

It seems your apic is unable to sync to its time server, is there a firewall in between ?

Please paste the output of ntpq -pcrv on the APIC controller?

Thanks

Alexander

[nexus13213]

Hi,

there is no firewall in between.

admin@APIC-01:~> ntpq -pcrv
     remote           refid      st t when poll reach   delay   offset  jitter
==============================================================================
 10.2.35.150     .INIT.          16 u    9   64    0    0.000    0.000   0.000
 10.2.35.172     .LOCL.           1 u    8   16  377    0.493  14391.5   0.060
associd=0 status=c016 leap_alarm, sync_unspec, 1 event, restart,
version="ntpd 4.2.8p10@1.3728-o Thu Aug 17 00:22:02 UTC 2017 (1)",
processor="x86_64", system="Linux/4.4.125.0.1insieme-1", leap=11,
stratum=16, precision=-24, rootdelay=0.000, rootdisp=6384.855,
refid=INIT, reftime=00000000.00000000  Thu, Feb  7 2036 13:28:16.000,
clock=dfa7ac6b.b9639adf  Tue, Nov 27 2018 18:43:39.724, peer=0, tc=3,
mintc=3, offset=0.000000, frequency=0.000, sys_jitter=0.000000,
clk_jitter=0.000, clk_wander=0.000
admin@APIC-01:~>

thanks, 

[p-smallwood]

I get the same problem where I get Fault F1700 and the NTP status shows my NTP server is stratum 1 with very low delay but a very high offset.

The other common factor between us is that we both have the NTP servers showing in "Polled in client mode" instead of "Selected for sync". I think we need to be "selected for sync". 

My local clock is about 9 hours slow and I think that this may be reflected in the very high offset figure and I suspect that with a high offset value the APIC is refusing to trust the NTP server.

I have waited for a day now to see if ACI might start to trust the NTP server and select it for sync.. but no joy.

I have removed the NTP server config and added it back in with no joy.