Configure NTP in ACI Fabric Solution

Introduction

This document describes how to configure the Network Time Protocol (NTP) in an Application Centric Infrastructure (ACI) fabric solution.

Prerequisites

Requirements

Cisco recommends that you have knowledge of these topics:

• Out-of-Band Management (OOB) on the Fabric
• NTP server

Components Used

The information in this document is based on these software and hardware versions:

• Application Policy Infrastructure Controller (APIC)
• Nexus 9500
• Nexus 9300

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, ensure that you understand the potential impact of any command.

Configure

Step 1. On the menu bar, navigate to FABRIC > FABRIC POLICIES.

In the Navigation pane, perform these actions:

• Expand Pod Policies
• Expand Policies
• Choose Date and Time

Step 2. Right click and choose Create Date and Time Policy as shown in the image.

Step 3. In the CREATE DATE AND TIME POLICY Wizard and STEP 1 > IDENTITY, enter these details:

• Enter Name.
• Enter Description.
• Choose Administrative State (enabled).
• Choose Authentication State (disabled).
• Click NEXT.

Step 4. STEP 2 > NTP SERVERS

• Specify the NTP servers to be used in this policy.
• Click + in order to add the NTP Servers.
• In the Create Providers Wizard, perform these actions:
  • Enter Name (which is Hostname or IP Address).
  • Enter Description.
  • Check the Preferred Box.
  • Minimum Polling Interval (4)
  • Maximum Polling Interval (6)
  • Select Management EPG (default (Out-of-Band))
  • Click OK.

Step 5. Click FINISH.

• In the Policies pane, navigate to Fabric > Fabric Policies > Pod Policies > Policies > Date and Time, choose DATE/TIME Format and perform these actions:
  • Choose Time Zone
  • Choose Display Format (local)
  • Choose Offset State (enabled)
  • Click SUBMIT.

Step 6. Update your POD Policy group in order to use your Date Time Policy.

Step 7. Assign New Policy Group as the DEFAULTFabric Policy Group.

• In the pane, navigate to Fabric > Fabric Policies > Pod Policies, choose default and in the Pod Selector - default work pane, perform these actions:
  • Enter Description.
  • Choose pod-policy-group as the Fabric Policy Group and as shown in the image.

Verify

Use this section in order to confirm that your configuration works properly.

From switches:

fabric1-leaf1# show ntp peers
--------------------------------------------------
  Peer IP Address               Serv/Peer
--------------------------------------------------
  172.16.129.235                Server (configured)





fabric1-leaf1# show ntp peer-status
Total peers : 1
* - selected for sync, + - peer mode(active),
- - peer mode(passive), = - polled in client mode
    remote                local                st   poll   reach delay   vrf
-------------------------------------------------------------------------------
*172.16.129.235          0.0.0.0               3    16     37    0.00134 management





fabric1-leaf1# show ntp statistics peer ipaddr 172.16.129.235
remote host:          172.16.129.235
local interface:      Unresolved
time last received:   2s
time until next send: 14s
reachability change:  408s
packets sent:         30
packets received:     30
bad authentication:   0
bogus origin:         0
duplicate:            0
bad dispersion:       0
bad reference time:   0
candidate order:      6
fabric1-leaf1#

From APIC:

admin@apic1:~> cat /etc/ntp.conf
OPTIONS="-u ntp:ntp -p /var/run/ntpd.pid"

# Permit time synchronization with our time source, but do not
# permit the source to query or modify the service on this system.
restrict default kod nomodify notrap nopeer noquery
restrict -6 default kod nomodify notrap nopeer noquery

# Permit all access over the loopback interface.  This could
# be tightened as well, but to do so would effect some of
# the administrative functions.
#restrict default ignore
restrict 127.0.0.1
#restrict -6 ::1

keysdir /etc/ntp/
keys /etc/ntp/keys

server 172.16.129.235 prefer minpoll 4 maxpoll 6

admin@apic1:~> ntpstat
synchronised to NTP server (172.16.129.235) at stratum 4
   time correct to within 268 ms
   polling server every 16 s

Troubleshoot

There is currently no specific information available to troubleshoot this configuration.