Skip to main content
Cisco SD-WAN
Support
Product Documentation
Viptela Documentation

NTP

Use the NTP template for all Viptela devices.

Configure network time protocol (NTP) servers on your Viptela devices in order to synchronize time across all devices in the Viptela overlay network. You can configure up to four NTP servers, and they must all be located or reachable in the same VPN.

Other devices are allowed to ask a Viptela device for the time, but no devices are allowed to use the Viptela device as an NTP server.

To configure NTP using vManage templates:

  1. Create an NTP feature template to configure NTP parameters, as described in this article.
  2. Configure the timezone in the System template. See the System help topic.

Navigate to the Template Screen

  1. In vManage NMS, select the Configuration ► Templates screen.
  2. In the Device tab, click Create Template.
  3. From the Create Template drop-down, select From Feature Template.
  4. From the Device Model drop-down, select the type of device for which you are creating the template.
  5. Under Additional System Templates, located to the right of the screen, click NTP.
  6. From the NTP drop-down, click Create Template. The NTP template form is displayed. The top of the form contains fields for naming the template, and the bottom contains fields for defining NTP parameters.

When you first open a feature template, for each parameter that has a default value, the scope is set to Default (indicated by a check mark), and the default setting or value is shown. To change the default or to enter a value, click the scope drop-down to the left of the parameter field and select one of the following:

Parameter Scope

Scope Description

Device Specific (indicated by a host icon)

Use a device-specific value for the parameter. For device-specific parameters, you cannot enter a value in the feature template. You enter the value when you attach a Viptela device to a device template.

When you click Device Specific, the Enter Key box opens. This box displays a key, which is a unique string that identifies the parameter in a CSV file that you create. This file is an Excel spreadsheet that contains one column for each key. The header row contains the key names (one key per column), and each row after that corresponds to a device and defines the values of the keys for that device. You upload the CSV file when you attach a Viptela device to a device template. For more information, see Create a Template Variables Spreadsheet.

To change the default key, type a new string and move the cursor out of the Enter Key box.

Examples of device-specific parameters are system IP address, hostname, GPS location, and site ID.

Global (indicated by a globe icon)

Enter a value for the parameter, and apply that value to all devices.

Examples of parameters that you might apply globally to a group of devices are DNS server, syslog server, and interface MTUs.

Minimum NTP Server Configuration

The following parameters are required (unless otherwise indicated) to configure an NTP. Select the Server tab and click the plus sign (+):

Step Parameter Name Description
 1. Template Name Enter a name for the template. It can be up to 128 characters and can contain only alphanumeric characters.
 2. Description (Template) Enter a description of the template. It can be up to 2048 characters and can contain only alphanumeric characters.
 3. Hostname or IP Address Click the plus sign (+), and enter the IP address of an NTP server or of a DNS server that knows how to reach the NTP server.
 4. Authentication Key Specify the MD5 key associated with the NTP server, to enable MD5 authentication. For the key to work, you must mark it as trusted in the Trusted field of the Authentication tab (discussed below).
 5. VPN

Enter the ID for the VPN to use to reach the NTP server or the VPN in which the NTP server is located. If you configure multiple NTP servers, they must all be located or reachable in the same VPN.

Range: 0 through 65530

 6. Version Enter the version number of the NTP protocol software.
Range: 1 through 4
Default: 4
 7. Source Interface (optional) Enter the name of a specific interface to use for outgoing NTP packets. The interface must be located in the same VPN as the NTP server. If it is not, the configuration is ignored.
 8. Prefer (optional) Click On if multiple NTP servers are at the same stratum level and you want one to be preferred. For servers at different stratum levels, the software chooses the one with the highest stratum level.
 9. Authentication Set up any authentication required by the NTP servers, as discussed below.
10. Save Click Save to save the feature template.

To add another NTP server, click the plus sign (+). You can configure up to four NTP servers. The Viptela software uses the server at the highest stratum level.

To delete an NTP server, click the trash icon to the right of the entry.

CLI equivalent:

system
  ntp
  ​  server (dns-server-address | ip-address)
      key key-id
      prefer
      source-interface interface-name
  ​    version number  ​    
      vpn vpn-id

Configure NTP Authentication

To configure authentication keys used to authenticate the NTP servers, select the Authentication tab and click the plus sign (+):

Parameter Name Description
Authentication

Click Authentication, and enter the following values:

  • Authentication Key—Enter an MD5 key ID. It can be a number from 1 through 65535.
  • Authentication Value—Enter either a cleartext key or an AES-encrypted key.
Trusted Click Trusted and enter the MD5 authentication key to designate the key as trustworthy. To associate this key with a server, enter the same value as you use for the the Authentication Key field on the Server tab.

CLI equivalent:

system
  ntp
    keys
      authentication key-id md5 md5-key
      trusted key-id

Release Information

Introduced in vManage NMS in Release 15.2.

  • Was this article helpful?