Cisco Catalyst 3750-X User Manual

7-5
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 7 Administering the Switch
Managing the System Time and Date
To disable NTP authentication, use the no ntp authenticate global configuration command. To remove
an authentication key, use the no ntp authentication-key number global configuration command. To
disable authentication of the identity of a device, use the no ntp trusted-key key-number global
configuration command.
This example shows how to configure the switch to synchronize only to devices providing authentication
k
ey 42 in the device’s NTP packets:
Switch(config)# ntp authenticate
Switch(config)# ntp authentication
-key 42 md5 aNiceKey
Switch(config)# ntp trusted-key 42
Configuring NTP Associations
An NTP association can be a peer association (this switch can either synchronize to the other device or
allow the other device to synchronize to it), or it can be a server association (meaning that only this
switch synchronizes to the other device, and not the other way around).
Step 3
ntp authentication-key number md5 value Define 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 the
se authentication keys, and the key number is specified by the
ntp trusted-key key-number command.
Step 4
ntp trusted-key key-number Specify one or more key numbers (defined in Step 3) that a peer
NTP device must provide in its NTP packets for this switch to
synchronize to it.
By default, no trusted keys are defined.
For k
ey-number, specify the key defined in Step 3.
This command provides protection agains
t accidentally
synchronizing the switch to a device that is not trusted.
Step 5
end Return to privileged EXEC mode.
Step 6
show running-config Verify your entries.
Step 7
copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose

Cisco Catalyst 3750-X Specifications

General

Switching Capacity	160 Gbps
Stacking Bandwidth	64 Gbps
Max Stacking Units	9
Layer Support	Layer 2 and Layer 3
Form Factor	Rack-mountable
DRAM	256 MB
Flash Memory	64 MB
Model	Cisco Catalyst 3750-X Series
Ports	24 or 48 10/100/1000 Ethernet ports
Uplink Interfaces	4 SFP or 2 SFP+
Features	StackWise Plus, EnergyWise
Image	IP Base or IP Services
Operating Temperature	0 to 40°C
Operating Humidity	10 to 85% noncondensing