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Software Configuration Guide—Release 15.0(2)SG
OL-23818-01
Chapter 47 Configuring Network Security with ACLs Configuring PACLs
Using PACL with Access-Group Mode
You can use the access group mode to change the way PA CLs in teract with other ACLs. For example, if
a Layer 2 interface belongs to VLAN100, VACL (VLAN filter) V1 is applied on VLAN100, and PACL
P1 is applied on the Layer 2 interface. In this situation, you must specify how P1 and V1 impact the
traffic with the Layer 2 interface on VLAN100. In a per-interface method, you can use the access-group
mode command to specify one of the following desired modes:
prefer port modeIf PACL is configured on a Layer 2 interface, then PACL takes effect and
overwrites the effect of other ACLs (Router ACL and VACL). If no PACL feature is configured on
the Layer 2 interface, other features applicable to the interface are merged and applied on the
interface. it is the default access group mode.
prefer VLAN modeVLAN-based ACL features take effect on the port if they have been applied on
the port and no PACLs are in effect. If no VLAN-based ACL features are applicable to the Layer 2
interface, then the PACL feature already on the interface is applied.
merge modeMerges applicable ACL features before they are programmed into the hardware.
Note Output PACLs are mutually exclusive with VACL and Router ACLs on Supervisor Engine II+. Access
group mode does not change the behavior of output traffic filtering.
Configuring Access-group Mode on Layer 2 Interface
To configure an access mode on a Layer 2 interface, perform this task:
This example shows how to merge and apply features other than PACL on the interface:
Switch# configure terminal
Switch(config)# interface fast 6/1
Switch(config-if)# access-group mode prefer port
This example shows how to merge applicable ACL features before they are programmed into hardware:
Switch# configure terminal
Switch(config)# interface fast 6/1
Switch(config-if)# access-group mode merge
Command Purpose
Step 1 Switch# configure terminal Enters global configuration mode.
Step 2 Switch(config)# interface interface Enters interface configuration mode.
Step 3 Switch(config-if)# [no] access-group mode
{prefer {port | vlan} | merge}Applies numbered or named ACL to the Layer 2 interface.
The no form deletes the IP or MAC ACL from the Layer 2
interface.
Step 4 Switch(config)# show running-config Displays the access list configuration.