7-4
Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter7 Administering the Switch
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:
Default NTP Configuration, page7-4
Configuring NTP Authentication, page7-5
Configuring NTP Associations, page7-6
Configuring NTP Broadcast Service, page7-7
Configuring NTP Access Restrictions, page7-8
Configuring the Source IP Address for NTP Packets, page7-10
Displaying the NTP Configuration, page7-11

Default NTP Configuration

Table 7 -1 shows the default NTP configuration.
NTP is enabled on all interfaces by default. All interfaces receive NTP packets.
Table7-1 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.