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Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
Chapter 4 Administering the Switch
Managing the System Time and Date
•
Configuring the Source IP Address for NTP Packets, page 4-10
•
Displaying the NTP Configuration, page 4-11
Default NTP Configuration
shows the default NTP configuration.
NTP is enabled on all interfaces by default. All interfaces receive NTP packets.
Configuring NTP Authentication
This procedure must be coordinated with the administrator of the NTP server; the information you
configure in this procedure must be matched by the servers used by the switch to synchronize its time to
the NTP server.
To authenticate the associations (communications between devices running NTP that provide for
accurate timekeeping) with other devices for security purposes, perform this task:
Table 4-1
Default NTP Configuration
Feature
Default Setting
NTP authentication
Disabled. No authentication key is specified.
NTP peer or server associations
None configured.
NTP broadcast service
Disabled; no interface sends or receives NTP broadcast packets.
NTP access restrictions
No access control is specified.
NTP packet source IP address
The source address is set by the outgoing interface.
Command
Purpose
Step 1
configure terminal
Enters global configuration mode.
Step 2
ntp authenticate
Enables the NTP authentication feature, which is disabled by
default.
Step 3
ntp authentication-key
number
md5
value
Defines the authentication keys. By default, none are defined.
•
For
number
, specify a key number. The range is 1 to
4294967295.
•
md5
specifies that message authentication support is provided
by using the message digest algorithm 5 (MD5).
•
For
value
, enter an arbitrary string of up to eight characters for
the key.
The switch does not synchronize to a device unless both have one
of these authentication keys, and the key number is specified by the
ntp trusted-key
key-number
command.
Summary of Contents for Catalyst 4500 Series
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