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Catalyst 3750 SwitchSoftware Configuration Guide
OL-8550-09
Chapter34 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.
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For frames going upstream from a host port to a promiscuous port, the VLAN map configured
on the secondary VLAN is applied.
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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 Chapter16,
“Configuring Private VLANs.”
For configuration examples, see the “Using VLAN Maps in Your Network” section on page34-35.
For information about using both router ACLs and VLAN maps, see the “VLAN Maps and Router ACL
Configuration Guidelines” section on page34-38.
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:
Use the no vlan access-map name global configuration command to delete a map. Use the no vlan
access-map name 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.
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 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.
Step3 action {drop | forward} (Optional) Set the action for the map entry. The default is to forward.
Step4 match {ip | mac} address {name |
number} [name | number]
Match the packet (using either the IP or MAC address) against one or more
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.
Step5 end Return to global configuration mode.
Step6 show running-config Display the access list configuration.
Step7 copy running-config startup-config (Optional) Save your entries in the configuration file.