Cisco Viptela NTP Configuration

Rashmi Bhardwaj | Blog,Config & Troubleshoot


NTP configuration is a basic system property which is configured at a system-wide level on all VIPTELA devices to keep their clocks synchronized. We configure the IP address or DNS name.

Cisco Viptela NTP Configuration

Configuration Steps

Hostname(config)# system

Hostname (config-system)# ntp ?

Possible completions:

keys     Configure NTP authentication keys

server   NTP server


Hostname (config-system)# ntp server (dns-server-address | ipv4-address) vpn vpn-id.

We can configure up to four NTP servers on a VIPTELA device and all these NTP servers must be located under same VPN. The server having the highest stratum value will be used. The stratum value of NTP server can be checked with the below command:

“show ntp stratum”.


We can also use MD5 authentication keys to access the NTP server.

NTP Configuration

Hostname (config-system)# ntp keys

Hostname (config-keys)# authentication key-id md5 md5-key

Key-id can be any value from 1 to 65535 and md5 key can be clear-text or AES-encrypted key.

To use an MD5 authentication key for an NTP server, the key must be configured to be trusted:

Hostname(config-system)# ntp keys trusted key-id

Finally, associate the MD5 authentication key with the NTP time server:

Hostname (config-system)# ntp server (dns-server-address |ipv4-address) key key-id

We can also define the source interface or IP address for the NTP packets as below:

Hostname (config-system)# ntp server <IP> source-interface <Interface name>

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.

We can also configure time-zone on VIPTELA devices which by default is UTC.

Hostname (config-system)# clock timezone timezone

Additionally VIPTELA devices in lab or testing environment can have the time configured locally on them but this setting is over written once the NTP configuration is done on the device.

Useful commands for verification of NTP setting as below:

Show ntp associations

Show ntp peer

Continue Reading:

Introduction to Cisco SD-WAN (Viptela)

Cisco Viptela Network Interfaces


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