Chapter 28
Configuring Network Security with ACLs
•
The time range relies on the switch system clock. Therefore, you need a reliable clock source. We
Note
recommend that you use Network Time Protocol (NTP) to synchronize the switch clock. For more
information, see the
Beginning in privileged EXEC mode, follow these steps to configure a time-range parameter for an ACL:
Command
Step 1
configure terminal
Step 2
time-range time-range-name
Step 3
absolute [start time date]
[end time date]
or
periodic day-of-the-week hh:mm to
[day-of-the-week] hh:mm
or
periodic {weekdays | weekend | daily}
hh:mm to hh:mm
Step 4
end
Step 5
show time-range
Step 6
copy running-config startup-config
To remove a configured time-range, use the no time-range time-range-name global configuration
command.
Repeat the steps if you have multiple items that you want operational at different times.
This example shows how to configure time ranges for workhours and for company holidays and how to
verify your configuration.
Switch(config)# time-range workhours
Switch(config-time-range)# periodic weekdays 8:00 to 12:00
Switch(config-time-range)# periodic weekdays 13:00 to 17:00
Switch(config-time-range)# exit
Switch(config)# time-range new_year_day_2000
Switch(config-time-range)# absolute start 00:00 1 Jan 2000 end 23:59 1 Jan 2000
Switch(config-time-range)# exit
Switch(config)# time-range thanksgiving_2000
Switch(config-time-range)# absolute start 00:00 22 Nov 2000 end 23:59 23 Nov 2000
Switch(config-time-range)# exit
Switch(config)# time-range christmas_2000
Switch(config-time-range)# absolute start 00:00 24 Dec 2000 end 23:50 25 Dec 2000
Switch(config-time-range)# end
Switch# show time-range
time-range entry: christmas_2000 (inactive)
absolute start 00:00 24 December 2000 end 23:50 25 December 2000
78-11380-12
You can control logging messages. ACL entries can log traffic at certain times of the day, but not
constantly. Therefore, you can simply deny access without having to analyze many logs generated
during peak hours.
"Managing the System Time and Date" section on page
Purpose
Enter global configuration mode.
Identify the time-range by a meaningful name (for example, workhours),
and enter time-range configuration mode. The name cannot contain a
space or quotation mark and must begin with a letter.
Specify when the function it will be applied to is operational. Use some
combination of these commands; multiple periodic statements are
allowed; only one absolute statement is allowed. If more than one
absolute statement is configured, only the one configured last is executed.
Return to privileged EXEC mode.
Verify the time-range configuration.
(Optional) Save your entries in the configuration file.
Catalyst 2950 and Catalyst 2955 Switch Software Configuration Guide
Configuring ACLs
7-1.
28-15