Description

This article explains the various ways in which EX switches behave on 'show ntp associations' output.  In every case, for example, when there is no route to NTP server or when the NTP server is inactive, we could go back and check what the problem is; whether the NTP is inactive or the route is available or not.

Symptoms

The output of 'show ntp associations' varies based on the reachability/connectivity to the NTP server.

Solution

Scenario1:

When NTP is configured on EX switch and when NTP server is reachable, the NTP server is active (with * sign) under 'show ntp associations' output:

{master:0}[edit]
user@switch# run ping 10.130.38.66
PING 10.130.38.66 (10.130.38.66): 56 data bytes
64 bytes from 10.130.38.66: icmp_seq=0 ttl=126 time=0.390 ms
64 bytes from 10.130.38.66: icmp_seq=1 ttl=126 time=0.500 ms

ntp {
    server 10.130.38.66;
}

{master:0}[edit]
user@switch# run show ntp associations
remote refid st t when poll reach delay offset jitter
==============================================================================
*10.130.38.66 80.80.83.32 2 - 7 16 1 0.465 -3.998 0.931

Scenario 2:

When NTP is configured on the EX switch and host with that IP is active in the network but NTP application is not running, the NTP server is listed under 'show ntp associations' command but not active (without * sign):

user@switch# run ping 10.130.238.100
PING 10.130.238.100 (10.130.238.100): 56 data bytes
64 bytes from 10.130.238.100: icmp_seq=0 ttl=254 time=1.315 ms
64 bytes from 10.130.238.100: icmp_seq=1 ttl=254 time=1.555 ms
user@switch# show system ntp
server 10.130.238.100;

user@switch> show ntp associations
remote refid st t when poll reach delay offset jitter
===============================================================
10.130.238.100 0.0.0.0 16 u 242 1024 0 0.000 0.000 4000.00

Scenario 3:

When NTP is configured and the NTP server connected interface is deleted, there is no output displayed under 'show ntp associations' command:

ser@switch# delete interfaces me0
[edit]
user@switch# commit
commit complete
[edit]
user@switch# run show ntp associations [edit]

user@switch# show system ntp
server 10.130.238.100;

Scenario 4:

When NTP is configured and no route to NTP server, the NTP server is listed under 'show ntp associations' command but not active (without * sign):

[edit]
user@switch# delete routing-options
[edit]
user@switch# commit
commit complete
[edit]
user@switch# show system ntp
server 10.130.238.100;
[edit]
user@switch# run show ntp associations
remote refid st t when poll reach delay offset jitter
=======================================================
10.130.238.100 0.0.0.0 16 - 17 64 0 0.000 0.000 4000.00

Scenario 5:

When NTP is not configured, RTO is seen under 'show ntp associations' command:

[edit]
user@switch# delete system ntp
[edit]
user@switch# commit
commit complete
[edit]
user@switch# run show ntp associations localhost: timed out, nothing received ***Request timed out

Modification History

2020-08-6: Article reviewed for accuracy; minor non-technical edits.