Specifications

4-7

System Management Software Configuration Guide for Cisco IE 2000U and Connected Grid Switches

Chapter 4 Administering the Switch

Configuring NTP

You can manage the system time and date on your switch using automatic configuration, such as the

Network Time Protocol (NTP), or manual configuration methods. For manual configuration, see the

“Configuring Time and Date Manually” section on page 4-15.

This section includes the following topics:

• Configuring NTP Authentication, page 4-7

• Configuring NTP Associations, page 4-8

• Configuring NTP Broadcast Service, page 4-10

• Configuring NTP Access Restrictions, page 4-11

• Configuring the Source IP Address for NTP Packets, page 4-14

Configuring NTP Authentication

Follow this procedure to authenticate the associations (communications between devices running NTP

that provide for accurate timekeeping) with other devices for security purposes.

BEFORE YOU BEGIN

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.

DETAILED STEPS

Command Purpose

Step 1

configure terminal Enter global configuration mode.

Step 2

ntp authenticate Enable the NTP authentication feature, which is disabled by

default.

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 these authentication keys, and the key number

is specified by the ntp trusted-key key-number command.