Cisco Catalyst 3750-X User Manual

7-9
Catalyst 3750-X and 3560-X Switch Software Configuration Guide
OL-21521-01
Chapter 7 Administering the Switch
Managing the System Time and Date
The access group keywords are scanned in this order, from least restrictive to most restrictive:
1. peer—Allows time requests and NTP control queries and allows the switch to synchronize itself to
a device whose address passes the access list criteria.
2. serve—Allows time requests and NTP control queries, but does not allow the switch to synchronize
itself to a device whose address passes the access list criteria.
3. serve-only—Allows only time requests from a device whose address passes the access list criteria.
4. query-only—Allows only NTP control queries from a device whose address passes the access list
criteria.
If the source IP address matches the access lists for more than
one access type, the first type is granted.
If no access groups are specified, all access types are granted to all devices. If any access groups are
specified, only the specified access types are granted.
To remove access control to the switch NTP services, use the no ntp access-gr
oup {query-only |
serve-only | serve | peer} global configuration command.
This example shows how to configure the switch to allo
w itself to synchronize to a peer from access
list 99. However, the switch restricts access to allo
w only time requests from access list 42:
Switch# configure terminal
Switch(config)# ntp access-group p
eer 99
Switch(config)# ntp access-group s
erve-only 42
Switch(config)# access-list 99 per
mit 172.20.130.5
Switch(config)# access list 42 per
mit 172.20.130.6
Step 3
access-list access-list-number permit
source [source-wildcard]
Create the access list.
• For access-list-number, enter the number specified in Step 2.
• Enter the permit keyword to permit access if the conditions are
matched.
• For source, enter the IP address of the device that is permitted access
to the switch.
• (Optional) For source-wildcard, enter the wildcard bits to be applied
to the source.
Note When creating an access list, remember that, by default, the end
of the access list contains an implicit deny statement for
everything if it did not find a match before reaching the end.
Step 4
end Return to privileged EXEC mode.
Step 5
show running-config Verify your entries.
Step 6
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