Configuring Authentication In Client Mode - Cisco WS-C2950SX-48-SI Configuration Manual

Configuring NTP on the Switch
This example shows how to configure the NTP server address, enable NTP client mode on the switch,
and verify the configuration:
Console> (enable) set ntp server 172.20.52.65
NTP server 172.20.52.65 added.
Console> (enable) set ntp client enable
NTP Client mode enabled
Console> (enable) show ntp
Current time: Tue Jun 23 1998, 20:29:25
Timezone: '', offset from UTC is 0 hours
Summertime: '', disabled
Last NTP update: Tue Jun 23 1998, 20:29:07
Broadcast client mode: disabled
Broadcast delay: 3000 microseconds
Client mode: enabled
NTP-Server
----------------------------------------
172.16.52.65
Console> (enable)

Configuring Authentication in Client Mode

Authentication can enhance the security of a system running NTP. When you enable the authentication
feature, the client switch sends time-of-day requests only to trusted NTP servers. The authentication
feature is documented in RFC 1305.
You can configure up to ten authentication keys per client. Each authentication key is actually a pair of
two keys:
•
•
To authenticate the message, the client authentication key must match the key on the server. Therefore,
the authentication key must be securely distributed in advance (the client administrator must get the key
pair from the server administrator and configure it on the client).
To configure authentication, perform this task in privileged mode:
Task
Step 1 Configure an authentication key pair for NTP and
specify whether the key will be trusted or untrusted.
Step 2
Set the IP address of the NTP server and the public
key.
Step 3
Enable NTP client mode.
Step 4
Enable NTP authentication.
Step 5 Verify the NTP configuration.
This example shows how to configure the NTP server address, enable NTP client and authentication
modes on the switch, and verify the configuration:
Console> (enable) set ntp server 172.20.52.65 key 879
NTP server 172.20.52.65 with key 879 added.
Catalyst 4500 Series, Catalyst 2948G, Catalyst 2980G Switches Software Configuration Guide
39-4
A public key number—A 32-bit integer that can range from 1–4,294,967,295
A secret key string—An arbitrary string of 32 characters, including all printable characters and
spaces
Chapter 39
Command
set ntp key public_key [trusted | untrusted] md5
secret_key
set ntp server ip_addr [key public_key]
set ntp client enable
set ntp authentication enable
show ntp [noalias]
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Release 8.1
Configuring NTP
78-15486-01