N3048 SNTP issue

Question

Hi,

I have a strange issue with my N3048 stack (two switches) selectively not synchronizing time with AD domain controllers. It works with one server added a long time ago, but every new NTP server added show an "Other" result. DoS protection is turned off. When checked from Windows, NTP is working fine. Could you please help me understand what is going on?

Notes:

In the results below, I replaced IP addresses with "Server A/B/C/D"
Server A doesn't share VLAN with others.
Server B and D are in the same VLAN.
The switch stack and server C are in the same VLAN.

#show sntp server

Server Host Address:               Server B
Server Type:                       IPv4
Server Stratum:                    3
Server Reference Id:               NTP Srv: Server A
Server Mode:                       Server
Server Maximum Entries:            8
Server Current Entries:            3

SNTP Servers
------------

Host Address: Server C
Address Type: IPv4
Priority: 1
Version: 4
Port: 123
Last Attempt Time: Jan  1 00:00:00 1970
Last Update Status: Other
Total Unicast Requests: 0
Failed Unicast Requests: 0

Host Address: Server B
Address Type: IPv4
Priority: 1
Version: 4
Port: 123
Last Update Time: Sep 19 08:12:41 2019
Last Attempt Time: Sep 19 08:19:05 2019
Last Update Status: Success
Total Unicast Requests: 43252
Failed Unicast Requests: 31

Host Address: Server D
Address Type: IPv4
Priority: 2
Version: 4
Port: 123
Last Attempt Time: Jan  1 00:00:00 1970
Last Update Status: Other
Total Unicast Requests: 0
Failed Unicast Requests: 0

#show clock

08:21:01 (UTC+0:00) Sep 19 2019
Time source is SNTP

#ping Server D
 Pinging Server D with 0 bytes of data:

Reply From Server D: icmp_seq = 0. time= 9912 usec.
Reply From Server D: icmp_seq = 1. time= 9785 usec.
Reply From Server D: icmp_seq = 2. time= 9572 usec.
Reply From Server D: icmp_seq = 3. time= 10579 usec.

----Server D PING statistics----
4 packets transmitted, 4 packets received, 0% packet loss
round-trip (msec) min/avg/max = 9/9/10

Windows CMD test:

net time \\Server D
Current time at \\Server D is ‎19.‎09.‎2019 10:22:01

The command completed successfully.

DELL-Josh Cr · Answer

Hi, Is the firmware up to date? There have been a few fixes to SNTP in a few of the updates.

Wilk- · Answer

unit active backup current-active next-active ---- ----------- ----------- -------------- -------------- 1 6.5.1.1 6.3.2.3 6.5.1.1 6.5.1.1 2 6.5.1.1 6.3.3.9 6.5.1.1 6.5.1.1 Thanks Josh. Apparently my switches are 'a little' behind... I will try to upgrade them to 6.5.4.4 and will let you know if that helped.

Wilk- · Answer

I'm sorry for the delay in answering. I updated my stack to 6.5.4.4 version, but unforunately it did not help. Do you have any other ideas?

#show clock

18:31:20 (UTC+0:00) Sep 30 2019
Time source is SNTP

#show sntp server

Server Host Address:               Server B
Server Type:                       IPv4
Server Stratum:                    3
Server Reference Id:               NTP Srv: Server A
Server Mode:                       Server
Server Maximum Entries:            8
Server Current Entries:            3

SNTP Servers
------------

Host Address: Server C
Address Type: IPv4
Priority: 1
Version: 4
Port: 123
Last Attempt Time: Jan  1 00:00:00 1970
Last Update Status: Other
Total Unicast Requests: 0
Failed Unicast Requests: 0

Host Address: Server B
Address Type: IPv4
Priority: 1
Version: 4
Port: 123
Last Update Time: Sep 30 18:23:23 2019
Last Attempt Time: Sep 30 18:28:43 2019
Last Update Status: Success
Total Unicast Requests: 8
Failed Unicast Requests: 0

Host Address: Server D
Address Type: IPv4
Priority: 2
Version: 4
Port: 123
Last Attempt Time: Jan  1 00:00:00 1970
Last Update Status: Other
Total Unicast Requests: 0
Failed Unicast Requests: 0

#show version

Machine Description............... Dell EMC Networking Switch
System Model ID................... N3048
Machine Type...................... Dell EMC Networking N3048
Serial Number..................... [redacted]
Manufacturer...................... 0xbc00
Burned In MAC Address............. [redacted]
System Object ID.................. [redacted]
SOC Version....................... BCM56340_A0
HW Version........................ 5
CPLD Version...................... 20
Image File........................ N3000AdvLitev6.5.4.4
Software Capability............... Stack Limit = 8, VLAN Limit = 1024

unit active      backup      current-active next-active
---- ----------- ----------- -------------- --------------
1    6.5.4.4     6.5.1.1     6.5.4.4        6.5.4.4
2    6.5.4.4     6.5.1.1     6.5.4.4        6.5.4.4

orbii · Answer

We have this exact same issue on N4064 - it only seems to be querying the second of three SNTP hosts. Dumping traffic it does not even seem to be attempting to send requests, which is reflected in the output:

Total Unicast Requests: 0
Failed Unicast Requests: 0

For whatever reason - it's not even attempting to connect.

Was this ever resolved in a newer version of software?

Dell-DylanJ · Answer

Hello,

This appears to be the latest version of firmware. I didn't see this issue mentioned in the notes, but it may be worth testing anyway.

https://www.dell.com/support/home/en-us/drivers/driversdetails?driverid=2c4jw

Networking General

N3048 SNTP issue

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