ntp not working

[Manish Manwal]

we have  one switch cisco 3850 configured as a ntp master. when we update another switch time form ntp server its update time but, its time is diffrent form our ntp master switch.

in ntp master we use just ntp master command and another switch we use ntp master switch loopback ip as a ntp server.

ntp server x.x.x.x

can someone give me  of ntp server and peer full configuration.

[Leo Laohoo]

If the 3850 is synchronizing NTP with an NTP server, don't (ever) use the command "ntp master".

[Manish Manwal]

there is no interface vlan 1. many vlan but not 1 , and switches are in different vlan.

mr georg pauwen whatever configuration you give me it not working.

[Georg Pauwen]

In addition to Leo's remark, below is what could work. It is a fairly simple setup:

NTP client

clock timezone GMT +1
clock summer-time PDT recurring
ntp server 1.1.1.1
interface GigabitEthernet 0/0
ntp broadcast

NTP Master

clock timezone GMT +1
clock summer-time PDT recurring
ntp master
interface Vlan 1
ntp broadcast

[Manish Manwal]

not working.
some other help needed
mr. Georg Pauwen

[balaji.bandi]

What is not working ?, can you post the configuration you have done.

show output related to  show ntp  Server and client to understand the issue.

[Georg Pauwen]

Hello,

post the full configs of both switches as well as the output of 'show ntp status'...

[rasmus.elmholt · Accepted solution]

Hi

Remember to set the clock on the 3850 and then the ntp master command.
If the 3850 is already configured with as a NTP client( ntp server x.x.x.x command) it will automaticaly become NTP server as well.

What does the show ntp ass command says on the ntp client? is it syncing?
And is the 3850 listening on port 123 UDP?
#show udp
Proto Remote Port Local Port In Out Stat TTY OutputIF
17 --listen-- 10.xx.xx.1 123 0 0 13001001 2
17(v6) --listen-- FE80::1 123 0 0 13020001 2

I find this best practise very useful: https://www.cisco.com/c/en/us/support/docs/availability/high-availability/19643-ntpm.html