Default Ntp Configuration - Cisco Catalyst 4500 Series Configuration Manual

Managing the System Time and Date
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Default NTP Configuration

Table 4-1
Table 4-1
Feature
NTP authentication
NTP peer or server associations
NTP broadcast service
NTP access restrictions
NTP packet source IP address
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:
Command
Step 1
configure terminal
Step 2
ntp authenticate
Step 3
ntp authentication-key number md5 value
Software Configuration Guide—Release IOS XE 3.3.0SG and IOS 15.1(1)SG
4-4
Configuring NTP Associations, page 4-6
Configuring NTP Broadcast Service, page 4-7
Configuring NTP Access Restrictions, page 4-8
Configuring the Source IP Address for NTP Packets, page 4-10
Displaying the NTP Configuration, page 4-11
shows the default NTP configuration.
Default NTP Configuration
Default Setting
Disabled. No authentication key is specified.
None configured.
Disabled; no interface sends or receives NTP broadcast packets.
No access control is specified.
The source address is set by the outgoing interface.
Purpose
Enters global configuration mode.
Enables the NTP authentication feature, which is disabled by
default.
Defines the authentication keys. By default, none are defined.
For number, specify a key number. The range is 1 to
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4294967295.
md5 specifies that message authentication support is provided
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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.
Chapter 4 Administering the Switch
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