Specifications

8-3
Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
78-11380-07
Chapter 8 Administering the Switch
Managing the System Time and Date
Several manufacturers include NTP software for their host systems, and a publicly available version for
systems running UNIX and its various derivatives is also available. This software allows host systems to
be time-synchronized as well.
Figure 8-1 Typical NTP Network Configuration
Configuring NTP
The Catalyst 2950 and 2955 switches do not have a hardware-supported clock, and they cannot function
as an NTP master clock to which peers synchronize themselves when an external NTP source is not
available. These switches also have no hardware support for a calendar. As a result, the ntp
update-calendar and the ntp master global configuration commands are not available.
This section contains this configuration information:
• Default NTP Configuration, page 8-4
• Configuring NTP Authentication, page 8-4
• Configuring NTP Associations, page 8-5
• Configuring NTP Broadcast Service, page 8-6
• Configuring NTP Access Restrictions, page 8-7
• Configuring the Source IP Address for NTP Packets, page 8-9
• Displaying the NTP Configuration, page 8-10
Catalyst 2950 or
3550 switch
Catalyst 2950 or
3550 switch
Catalyst 2950 or
3550 switch
Catalyst 2950 or
3550 switch
These switches are configured in
NTP server mode (server association)
with the Catalyst 6500 series switch.
Catalyst 6500
series switch
(NTP master)
This switch is configured as an NTP
peer to the upstream and downstream
Catalyst 3550 switches.
Catalyst 2950 or
3550 switch
Workstations
Workstations
Local
workgroup
servers
74722