Virtualization Support; Licensing Requirements For Ntp; Prerequisites For Ntp; Guidelines And Limitations For Ntp - Cisco Nexus 7000 Series Configuration Manual

Virtualization Support

Virtualization Support
If you are running a Cisco NX-OS Release prior to 5.2, up to one instance of NTP is supported on the entire
platform. You must configure NTP in the default virtual device context (VDC), and you are automatically
placed in the default VDC unless you specify otherwise.
If you are running Cisco NX-OS Release 5.2 or later, multiple instances of NTP are supported, one instance
per VDC. By default, Cisco NX-OS places you in the default VDC unless you specifically configure another
VDC. Only one VDC (the default VDC by default) synchronizes the system clock at any given time. The
NTP daemon in all other VDCs acts only as an NTP server for the other devices. To change which VDC
synchronizes the system clock, use the clock protocol ntp vdc vdc-id command.
NTP recognizes virtual routing and forwarding (VRF) instances. NTP uses the default VRF if you do not
configure a specific VRF for the NTP server and NTP peer. See the Cisco Nexus 7000 Series NX-OS Unicast
Routing Configuration Guide for more information about VRFs.
For more information about VDCs, see the Cisco Nexus 7000 Series NX-OS Virtual Device Context
Configuration Guide.

Licensing Requirements for NTP

Product
Cisco
NX-OS

Prerequisites for NTP

NTP has the following prerequisites:
• To configure NTP, you must have connectivity to at least one server that is running NTP.
• To configure VDCs, you must install the appropriate license. See the Cisco Nexus 7000 Series NX-OS

Guidelines and Limitations for NTP

NTP has the following configuration guidelines and limitations:
• The Cisco NX-OS software supports NTP version 4 (NTPv4).
• NTP server functionality is supported.
• You should have a peer association with another device only when you are sure that your clock is reliable
Cisco Nexus 7000 Series NX-OS System Management Configuration Guide
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License Requirement
NTP requires no license. Any feature not included in a license package is bundled with the
nx-os image and is provided at no extra charge to you. For a complete explanation of the
Cisco NX-OS licensing scheme, see the Cisco NX-OS Licensing Guide.
Virtual Device Context Configuration Guide for configuration information and the Cisco NX-OS Licensing
Guide for licensing information.
(which means that you are a client of a reliable NTP server).
Configuring NTP