Chapter 23 Configuring Network Security

Configuring VLAN ACLs

VLAN Access Map Configuration and Verification Examples, page 23-15

Configuring a Capture Port, page 23-16

VACL Configuration Overview

VACLs use standard and extended Cisco IOS IP and IPX ACLs, and MAC-Layer named ACLs (see the “Configuring MAC-Layer Named Access Lists (Optional)” section on page 32-39) and VLAN access maps.

VLAN access maps can be applied to VLANs or, with releases 12.1(13)E or later, to WAN interfaces for VACL capture. VACLs attached to WAN interfaces support only standard and extended Cisco IOS IP ACLs for VACL capture.

Each VLAN access map can consist of one or more map sequences, each sequence with a match clause and an action clause. The match clause specifies IP, IPX, or MAC ACLs for traffic filtering and the action clause specifies the action to be taken when a match occurs. When a flow matches a permit ACL entry, the associated action is taken and the flow is not checked against the remaining sequences. When a flow matches a deny ACL entry, it will be checked against the next ACL in the same sequence or the next sequence. If a flow does not match any ACL entry and at least one ACL is configured for that packet type, the packet is denied.

To use access-control for both bridged and routed traffic, you can use VACLs alone or a combination of VACLs and ACLs. You can define ACLs on the VLAN interfaces to use access-control for both the input and output routed traffic. You can define a VACL to use access-control for the bridged traffic.

The following caveats apply to ACLs when used with VACLs:

Packets that require logging on the outbound ACLs are not logged if they are denied by a VACL.

VACLs are applied on packets before NAT translation. If the translated flow is not subject to access control, the flow might be subject to access control after the translation because of the VACL configuration.

The action clause in a VACL can be forward, drop, capture, or redirect. Traffic can also be logged. VACLs applied to WAN interfaces do not support the redirect or log actions.

Note VACLs have an implicit deny at the end of the map; a packet is denied if it does not match any ACL entry, and at least one ACL is configured for the packet type.

Note If an empty or undefined ACL is specified in a VACL, any packets will match the ACL and the associated action is taken.

Defining a VLAN Access Map

To define a VLAN access map, perform this task:

 

Command

Purpose

 

 

 

 

Router(config)# vlan access-map map_name [0-65535]

Defines the VLAN access map. Optionally, you can specify

 

 

 

 

the VLAN access map sequence number.

 

Router(config)# no vlan access-map map_name 0-65535

Deletes a map sequence from the VLAN access map.

 

Router(config)# no vlan access-map map_name

Deletes the VLAN access map.

 

 

 

 

 

 

 

 

Cisco 7600 Series Router Cisco IOS Software Configuration Guide—12.1E

 

 

 

 

 

 

 

 

 

 

23-12

 

 

78-14064-04

 

 

 

 

 

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Cisco Systems 7600 SERIES manual Vacl Configuration Overview, Defining a Vlan Access Map, 23-12