37-11
Cisco IE 2000 Switch Software Configuration Guide
OL-25866-01
Chapter 37 Configuring Network Security with ACLs
How to Configure Network Security with ACLs
To determine the specialized hardware resources, enter the show platform layer4 acl map privileged
EXEC command. If the switch does not have available resources, the output shows that index 0 to
index 15 are not available.
For more information about configuring ACLs with insufficient resources, see CSCsq63926 in the Bug
Toolkit.

Named MAC Extended ACLs

You can filter non-IPv4 traffic on a VLAN or on a Layer 2 interface by using MAC addresses and named
MAC extended ACLs. The procedure is similar to that of configuring other extended nam ed ACLs.
Note You cannot apply named MAC extended ACLs to Layer 3 interfaces.
Note Though visible in the command-line help strings, appletalk is not supported as a matching condi tion for
the deny and permit MAC access-list configuration mode commands.

MAC ACL to a Layer 2 Interface

After you create a MAC ACL, you can apply it to a Layer 2 interfa ce to filter non-IP traffic coming in
that interface. When you apply the MAC ACL, consider these guidelines:
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 an input Layer 3 ACL applied to the VLAN interface. Incoming packets
received on the Layer 2 port are always filtered by the port ACL.
You can apply no more than one IP access list and one MAC access list to the same Layer 2 interface.
The IP access list filters only IP packets, and the MAC access list filters non-IP packets.
A Layer 2 interface can have only one MAC access list. If you apply a MAC access list to a Layer 2
interface that has a MAC ACL configured, the new ACL replaces the previously configured one.
How to Configure Network Security with ACLs

Creating a Numbered Standard ACL

Note When creating an ACL, remember that, by default, the end of the ACL contains an implicit deny
statement for all packets that it did not find a match for before reaching the end. With standard access
lists, if you omit the mask from an associated IP host address ACL specification, 0.0.0.0 is assumed to
be the mask.