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Cisco Catalyst Blade Switch 3130 for Dell Software Configuration Guide
OL-13270-01
Chapter6 Administering the Switch
Managing the System Time and Date
To disable an interface from receiving NTP broadcast packets, use the no ntp broadcast client interface
configuration command. To change the estimated round-trip delay to the d efau lt, us e the no ntp
broadcastdelay global configuration command.
This example shows how to configure a port to receive NTP broadcast packets:
Switch(config)# interface gigabitethernet1/0/1
Switch(config-if)# ntp broadcast client
Configuring NTP Access Restrictions
You can control NTP access on two levels as described in these sections:
Creating an Access Group and Assigning a Basic IP Access List, page6-8
Disabling NTP Services on a Specific Interface, page6-10

Creating an Access Group and Assigning a Basic IP Access List

Beginning in privileged EXEC mode, follow these steps to control access to NTP services by using
access lists:
Step5 ntp broadcastdelay microseconds (Optional) Change the estimated round-trip delay between the switch and
the NTP broadcast server.
The default is 3000 microseconds; the range is 1 to 999999.
Step6 end Return to privileged EXEC mode.
Step7 show running-config Verify your entries.
Step8 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 ntp access-group {query-only |
serve-only | serve | peer}
access-list-number
Create an access group, and apply a basic IP access list.
The keywords have these meanings:
query-only—Allows only NTP control queries.
serve-only—Allows only time requests.
serve—Allows time requests and NTP control queries, but does not
allow the switch to synchronize to the remote device.
peer—Allows time requests and NTP control queries and allows the
switch to synchronize to the remote device.
For access-list-number, enter a standard IP access list number from 1
to 99.