Cisco Systems 3750E Creating a Vlan Map, Vlan access-map name number, Action drop forward, 34-31

Chapter 34 Configuring Network Security with ACLs

Configuring VLAN Maps

•When a frame is Layer-2 forwarded within a private VLAN, the same VLAN map is applied at the ingress side and at the egress side. When a frame is routed from inside a private VLAN to an external port, the private-VLAN map is applied at the ingress side.

–For frames going upstream from a host port to a promiscuous port, the VLAN map configured on the secondary VLAN is applied.

–For frames going downstream from a promiscuous port to a host port, the VLAN map configured on the primary VLAN is applied.

To filter out specific IP traffic for a private VLAN, you should apply the VLAN map to both the primary and secondary VLANs. For more information about private VLANs, see Chapter 16, “Configuring Private VLANs.”

For configuration examples, see the “Using VLAN Maps in Your Network” section on page 34-34.

For information about using both router ACLs and VLAN maps, see the “VLAN Maps and Router ACL Configuration Guidelines” section on page 34-37.

Creating a VLAN Map

Each VLAN map consists of an ordered series of entries. Beginning in privileged EXEC mode, follow these steps to create, add to, or delete a VLAN map entry:

	Command	Purpose
Step 1
	configure terminal	Enter global configuration mode.
Step 2
	vlan access-map name [number]	Create a VLAN map, and give it a name and (optionally) a number. The
		number is the sequence number of the entry within the map.
		When you create VLAN maps with the same name, numbers are assigned
		sequentially in increments of 10. When modifying or deleting maps, you
		can enter the number of the map entry that you want to modify or delete.
		Entering this command changes to access-map configuration mode.
Step 3
	action {drop forward}	(Optional) Set the action for the map entry. The default is to forward.
Step 4 match {ip mac} address {name		Match the packet (using either the IP or MAC address) against one or more
	number} [name number]	standard or extended access lists. Note that packets are only matched
		against access lists of the correct protocol type. IP packets are matched
		against standard or extended IP access lists. Non-IP packets are only
		matched against named MAC extended access lists.
Step 5
	end	Return to global configuration mode.
Step 6
	show running-config	Display the access list configuration.
Step 7
	copy running-config startup-config	(Optional) Save your entries in the configuration file.

Use the no vlan access-mapname global configuration command to delete a map. Use the no vlan access-mapname number global configuration command to delete a single sequence entry from within the map.

Use the no action access-map configuration command to enforce the default action, which is to forward.

VLAN maps do not use the specific permit or deny keywords. To deny a packet by using VLAN maps, create an ACL that would match the packet, and set the action to drop. A permit in the ACL counts as a match. A deny in the ACL means no match.

	Catalyst 3750-E and 3560-E Switch Software Configuration Guide
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