Configuring NTP
Virtualization Support
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 9000 Series NX-OS Unicast
Routing Configuration Guide for more information about VRFs.
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.
Guidelines and Limitations for NTP
NTP has the following configuration guidelines and limitations:
• NTP server functionality is supported.
• You should have a peer association with another device only when you are sure that your clock is reliable
• A peer configured alone takes on the role of a server and should be used as a backup. If you have two
• If you have only one server, you should configure all the devices as clients to that server.
• You can configure up to 64 NTP entities (servers and peers).
• If you configure NTP in a VRF, ensure that the NTP server and peers can reach each other through the
• You must manually distribute NTP authentication keys on the NTP server and Cisco NX-OS devices
• If you are using the switch as an edge device and want to use NTP, Cisco recommends using the ntp
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.
(which means that you are a client of a reliable NTP server).
servers, you can configure several devices to point to one server and the remaining devices to point to
the other server. You can then configure a peer association between these two servers to create a more
reliable NTP configuration.
configured VRFs.
across the network.
access-group command and filtering NTP only to the required edge devices.
Cisco Nexus 9000 Series NX-OS System Management Configuration Guide, Release 6.x
Virtualization Support
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