configure NTP on cisco nexus 7k

[eugenio desideri]

hi there folks , i've got a problem getting ntp synch on my nexus

in my infrastructure 2 ASR connected to the nexus are serving  as ntp servers and 60 cat4500 are connected to the nexus as L2 switches

all my cat4500 seems to be sychronized ..below the show ntp status :

Clock is synchronized, stratum 5, reference is 10.32.253.22  
nominal freq is 119.2092 Hz, actual freq is 119.2132 Hz, precision is 2**17
reference time is D9746D3C.AF6E2479 (14:46:52.685 METDST+1 Tue Aug 11 2015)
clock offset is -0.5251 msec, root delay is 5.83 msec
root dispersion is 7969.54 msec, peer dispersion is 1942.83 msec
loopfilter state is 'CTRL' (Normal Controlled Loop), drift is -0.000033184 s/s
system poll interval is 64, last update was 416 sec ago.

this is the nexus conf :

ip access-list copp-system-acl-ntp
  10 permit udp any any eq ntp
  20 permit udp any eq ntp any
ipv6 access-list copp-system-acl-ntp6
  10 permit udp any any eq ntp
  20 permit udp any eq ntp any
  match access-group name copp-system-acl-ntp
  match access-group name copp-system-acl-ntp6
ntp server 10.32.253.21 prefer use-vrf lombardia_mngt
ntp server 10.32.253.22 use-vrf lombardia_mngt
ntp source-interface  Vlan2550
ntp logging

now....i know very few about how NTP works .....

but it seems to me very strange

what a " show ntp status " shows ....

#sh ntp status

Distribution : Disabled
Last operational state: No session

any clue??

thx

[Mark Malone]

Hi make sure the feature is on -feature ntp- and its enabled -ntp enable-

Verification is different than ios check the show clock detail make you should see time source is ntp

and show ntp peers

also it should just work with ntp server x.x.x.x thats all i have set on my Nexus switches and ntp is working fine

HTH

Edit

This may help

http://www.cisco.com/c/en/us/td/docs/switches/datacenter/sw/4_2/nx-os/system_management/configuration/guide/sm_nx_os_cli/sm_3ntp.html#wp1071821

[eugenio desideri]

the ntp feature is active , but the output i get dont says "time source is NTP" ( see below)

VDC2# sh clock detail
12:29:24.054 GMT Wed Aug 19 2015
summer-time configuration:
--------------------------
timezone name: GMT
starts       : 5 sunday march at 03:00 hours
Ends         : 5 sunday october at 02:00 hours
Minute offset: 60

[Martin Hruby]

Hello Eugenio

What is the output of the show ntp peer-status command?

Best regards,
Martin

[eugenio desideri]

this is the output

VDC2# 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
-------------------------------------------------------------------------------
*10.32.253.21           10.33.255.252           4   64     377   0.00264 lombardia_mngt
=10.32.253.22           10.33.255.252           4   64     377   0.00171 lombardia_mngt

[Mark Malone]

That looks fine I wouldn't worry about the show clock detail not showing ntp it could be just the os version has different output

7kdis1# sh ntp peer-status
Total peers : 3
* - selected for sync, + -  peer mode(active),
- - peer mode(passive), = - polled in client mode
    remote               local                 st   poll   reach delay   vrf
-------------------------------------------------------------------------------
*172.21.17.110          0.0.0.0                 4   64     377   0.00066 management
=172.21.7.110           0.0.0.0                 5   64     377   0.00058 management
=172.21.7.111           0.0.0.0                 4   64     377   0.00070 management
 

[Martin Hruby]

Hello Eugenio

This is correct, your switch is synchronizing with 10.32.253.21.

On my switches with NX-OS 7.0(5)N1(1), the show clock detail command also doesn't show NTP as a time source.

Best regards,
Martin