Reference Guide

Time and Network Time Protocol (NTP) | 1437
Usage
Information
After configuring the ntp authentication-key command, configure the ntp trusted-key command to
complete NTP authentication.
FTOS versions 8.2.1.0 and later use an encryption algorithm to store the authentication key that is
different from previous FTOS versions; beginning in version 8.2.1.0, FTOS uses DES encryption to
store the key in the startup-config when you enter the command ntp authentication-key. Therefore,
if your system boots with a startup-configuration from an FTOS versions prior to 8.2.1.0 in which you
have configured ntp authentication-key, the system cannot correctly decrypt the key, and cannot
authenticate NTP packets. In this case you must re-enter this command and save the running-config to
the startup-config.
Related
Commands
ntp broadcast client
c e s
Set up the interface to receive NTP broadcasts from an NTP server.
Syntax
ntp broadcast client
To disable broadcast, enter no ntp broadcast client.
Defaults
Disabled
Command Modes
INTERFACE
Command
History
ntp disable
c e s
Prevent an interface from receiving NTP packets.
Syntax
ntp disable
To re-enable NTP on an interface, enter no ntp disable.
Default
Disabled (that is, if an NTP host is configured, all interfaces receive NTP packets)
Command Modes
INTERFACE
Command
History
ntp authenticate Enables NTP authentication.
ntp trusted-key Configure a trusted key.
Version 7.6.1.0 Support added for S-Series
Version 7.5.1.0 Support added for C-Series
pre-Version 6.1.1.0 Introduced for E-Series
Version 7.6.1.0 Support added for S-Series
Version 7.5.1.0 Support added for C-Series
pre-Version 6.1.1.0 Introduced for E-Series