Configuring Ntp; Default Ntp Configuration - Cisco Catalyst 3750-E Software Configuration Manual

Managing the System Time and Date

Configuring NTP

The switch does not have a hardware-supported clock and cannot function as an NTP master clock to
which peers synchronize themselves when an external NTP source is not available. The switch also has
no hardware support for a calendar. As a result, the ntp update-calendar and the ntp master global
configuration commands are not available.
These sections contain this configuration information:
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Default NTP Configuration

Table 7-1
Table 7-1
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.
Beginning in privileged EXEC mode, follow these steps to authenticate the associations (communications
between devices running NTP that provide for accurate timekeeping) with other devices for security
purposes:
Command
Step 1 configure terminal
Step 2 ntp authenticate
Catalyst 3750-E and 3560-E Switch Software Configuration Guide
7-4
Default NTP Configuration, page 7-4
Configuring NTP Authentication, page 7-4
Configuring NTP Associations, page 7-5
Configuring NTP Broadcast Service, page 7-6
Configuring NTP Access Restrictions, page 7-8
Configuring the Source IP Address for NTP Packets, page 7-10
Displaying the NTP Configuration, page 7-11
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
Enter global configuration mode.
Enable the NTP authentication feature, which is disabled by
default.
Chapter 7 Administering the Switch
OL-9775-08