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Software Configuration Guide—Release 15.0(2)SG
OL-23818-01
Chapter 4 Administering the Switch Managing the System Time and Date
To disable NTP authentication, use the no ntp authenticate global configuration command. To remove
an authentication key, use the no ntp authentication-key number global configuration command. To
disable authentication of the identity of a device, use the no ntp trusted-key key-number global
configuration command.
This example shows how to configure the switch to synchronize only to devices providing authentication
key 42 in the device’s NTP packets:
Switch# configure terminal
Switch(config)# ntp authenticate
Switch(config)# ntp authentication-key 42 md5 aNiceKey
Switch(config)# ntp trusted-key 42
Switch(config)# end
Switch#
Step 4 ntp trusted-key key-number Specifies one or more key numbers (defined in Step 3) that a peer
NTP device must provide in its NTP packets for this switch to
synchronize to it.
By default, no trusted keys are defined.
For key-number, specify the key defined in Step 3.
This command provides protection against accidentally
synchronizing the switch to a device that is not trusted.
Step 5 end Returns to privileged EXEC mode.
Step 6 show running-config Verifies your entries.
Step 7 copy running-config startup-config (Optional) Saves your entries in the configuration file.
Command Purpose