Configuring NTP

kevdpc · ‎09-08-2020

I'm configuring NTP in Cisco UCS Manager. I have all of the settings correct and our firewall person confirmed that the fabric interconnects and their VIPs are allowed through to our NTP server. The UCSM time has been ahead by 50 seconds for weeks though. Is there a service I need to restart or something more that I need to do in order to get them to sync up?

balaji.bandi · ‎09-08-2020

as long as it sync with your NTP server and your time zone set correctly - you should see same time your NTP Server

check the below guide and re-configure.

https://www.unixarena.com/2015/08/cisco-ucs-configuring-ntp-and-configuration-backup.html/

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Ruben Cocheno · ‎09-08-2020

@kevdpc

Confirm that your NTP across is the same, also the timezone/Daylight Saving Time, also if you have multiple NTP's it migh be syncing through a prefered one.

Tag me to follow up.
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Kirk J · ‎09-09-2020

Greetings.

You might want to open a couple of SSH sessions with your UCSM VIP ip.

connect nxos

ethanalyzer local interface mgmt capture-filter "port 123" limit-captured-frames 0 detail

on the 2nd session run: ntp sync-retry

Check your ethanlyzer output for section called 'Network Time Protocol'

Kirk...

kevdpc · ‎09-10-2020

Here's the Network Time Protocol output [with some edits] for Frames 1-4. Frames 1 and 2 look bad, frame 3 looks good, and frame 4 I don't know where Reference Clock ID: 132.163.96.6 comes from.

Frame 1

Network Time Protocol
Flags: 0xd3
11.. .... = Leap Indicator: alarm condition (clock not synchronized) (3)
..01 0... = Version number: NTP Version 2 (2)
.... .011 = Mode: client (3)
Peer Clock Stratum: unspecified or unavailable (0)
Peer Polling Interval: 4 (16 sec)
Peer Clock Precision: 0.000001 sec
Root Delay: 0.0000 sec
Root Dispersion: 0.0000 sec
Reference Clock ID: (Initialization)
Reference Clock Update Time: NULL
Originate Time Stamp: NULL
Receive Time Stamp: NULL
Transmit Time Stamp: Sep 10, 2020 14:01:51.3248 UTC

*****

Frame 2

Network Time Protocol
Flags: 0xd3
11.. .... = Leap Indicator: alarm condition (clock not synchronized) (3)
..01 0... = Version number: NTP Version 2 (2)
.... .011 = Mode: client (3)
Peer Clock Stratum: unspecified or unavailable (0)
Peer Polling Interval: 4 (16 sec)
Peer Clock Precision: 0.000001 sec
Root Delay: 0.0000 sec
Root Dispersion: 0.0000 sec
Reference Clock ID: (Initialization)
Reference Clock Update Time: NULL
Originate Time Stamp: NULL
Receive Time Stamp: NULL
Transmit Time Stamp: Sep 10, 2020 14:01:51.3251 UTC

*****

Frame 3

Network Time Protocol
Flags: 0x1c
00.. .... = Leap Indicator: no warning (0)
..01 1... = Version number: NTP Version 3 (3)
.... .100 = Mode: server (4)
Peer Clock Stratum: secondary reference (3)
Peer Polling Interval: 4 (16 sec)
Peer Clock Precision: 0.000000 sec
Root Delay: 0.0534 sec
Root Dispersion: 0.0566 sec
Reference Clock ID: [correct primary NTP SERVER IP shown here]
Reference Clock Update Time: Sep 10, 2020 13:56:53.4350 UTC
Originate Time Stamp: Sep 10, 2020 14:01:51.3248 UTC
Receive Time Stamp: Sep 10, 2020 14:01:51.3260 UTC
Transmit Time Stamp: Sep 10, 2020 14:01:51.3260 UTC

*****

Frame 4

Network Time Protocol
Flags: 0x1c
00.. .... = Leap Indicator: no warning (0)
..01 1... = Version number: NTP Version 3 (3)
.... .100 = Mode: server (4)
Peer Clock Stratum: secondary reference (2)
Peer Polling Interval: 4 (16 sec)
Peer Clock Precision: 0.000000 sec
Root Delay: 0.0494 sec
Root Dispersion: 0.0264 sec
Reference Clock ID: 132.163.96.6
Reference Clock Update Time: Sep 10, 2020 13:57:13.5598 UTC
Originate Time Stamp: Sep 10, 2020 14:01:51.3251 UTC
Receive Time Stamp: Sep 10, 2020 14:01:51.3248 UTC
Transmit Time Stamp: Sep 10, 2020 14:01:51.3248 UTC

kevdpc · ‎09-10-2020

Is it possible that udp/123 needs to be allowed in both directions? NTP servers to FIs and FIs to NTP servers?

To check the time sync I'm comparing my Windows time (which shows seconds) with the UCSM system time (which does not show seconds) below. Is it possible that the time is actually synchronized just fine but the UCSM system time isn't refreshing often enough? Is there a way for me to view the live system time with seconds?

Kirk J · ‎09-10-2020

connect nxos

show clock

Kirk...

kevdpc · ‎09-10-2020

The show clock command shows perfectly synchronized time with my NTP servers. I was mislead by the system time in UCSM not refreshing often enough!!