Port Acls - Cisco 4500M Software Manual

Understanding ACLs
Figure 35-1 Using ACLs to Control Traffic to a Network

Port ACLs

You can also apply ACLs to Layer 2 interfaces on a switch. Port ACLs are supported on physical
interfaces and EtherChannel interfaces.
The following access lists are supported on Layer 2 interfaces:
•
•
•
As with router ACLs, the switch examines ACLs associated with features configured on a given interface
and permits or denies packet forwarding based on how the packet matches the entries in the ACL. In the
example in
would allow Host A to access the Human Resources network, but prevent Host B from accessing the
same network.
When you apply a port ACL to a trunk port, the ACL filters traffic on all VLANs present on the trunk
port. When you apply a port ACL to a port with voice VLAN, the ACL filters traffic on both data and
voice VLANs.
With port ACLs, you can filter IP traffic by using IP access lists and non-IP traffic by using MAC
addresses. You can filter both IP and non-IP traffic on the same Layer 2 interface by applying both an IP
access list and a MAC access list to the interface.
You cannot apply more than one IP access list and one MAC access list to a Layer 2 interface. If an IP
Note
access list or MAC access list is already configured on a Layer 2 interface and you apply a new IP access
list or MAC access list to the interface, the new ACL replaces the previously configured one.
Software Configuration Guide—Release 12.2(25)EW
35-4
Catalyst 4500 series switch
Si
Human
Resources
network
= ACL denying traffic from Host B
and permitting traffic from Host A
= Packet
Standard IP access lists using source addresses
Extended IP access lists using source and destination addresses and optional protocol type
information
MAC extended access lists using source and destination MAC addresses and optional protocol type
information
Figure 35-1, if all workstations were in the same VLAN, ACLs applied at the Layer 2 input
Chapter 35
Host A
Host B
Research &
Development
network
Configuring Network Security with ACLs
OL-6696-01