Specifications

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Catalyst 2970 Switch Software Configuration Guide
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Chapter 26 Configuring Network Security with ACLs
Configuring IP ACLs
Applying an IP ACL to a Terminal Line
You can use numbered ACLs to control access to one or more terminal lines. You cannot apply named
ACLs to lines. You must set identical restrictions on all the virtual terminal lines because a user can
attempt to connect to any of them.
For procedures for applying ACLs to interfaces, see the “Applying an IP ACL to an Interface” section
on page 26-16. For applying ACLs to VLANs, see the “Configuring VLAN Maps” section on
page 26-22.
Beginning in privileged EXEC mode, follow these steps to restrict incoming and outgoing connections
between a virtual terminal line and the addresses in an ACL:
To remove an ACL from a terminal line, use the no access-class access-list-number {in | out} line
configuration command.
Applying an IP ACL to an Interface
This section describes how to apply IP ACLs to network interfaces. You can apply ACLs only to inbound
Layer 2 interfaces. Note these guidelines:
• When controlling access to an interface, you can use a named or numbered ACL.
• If you apply an ACL to a Layer 2 interface that is a member of a VLAN, the Layer 2 (port) ACL
takes precedence over a VLAN map applied to the VLAN. Incoming packets received on the Layer
2 port are always filtered by the port ACL.
Beginning in privileged EXEC mode, follow these steps to control access to an interface:
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
line [console | vty] line-number Identify a specific line to configure, and enter in-line configuration mode.
• console—Specify the console terminal line. The console port is DCE.
• vty—Specify a virtual terminal for remote console access.
The line-number is the first line number in a contiguous group that you want
to configure when the line type is specified. The range is from 0 to 16.
Step 3
access-class access-list-number
{in | out}
Restrict incoming and outgoing connections between a particular virtual
terminal line (into a device) and the addresses in an access list.
Step 4
end Return to privileged EXEC mode.
Step 5
show running-config Display the access list configuration.
Step 6
copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose
Step 1
configure terminal Enter global configuration mode.
Step 2
interface interface-id Identify a specific interface for configuration, and enter interface
configuration mode.