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Catalyst 3550 Multilayer Switch Software Configuration Guide
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Chapter 28 Configuring Network Security with ACLs
Configuring VLAN Maps
VLAN Map Configuration Guidelines
Follow these guidelines when configuring VLAN maps:
•
If there is no router ACL configured to deny traffic on a routed VLAN interface (input or output),
and no VLAN map configured, all traffic is permitted.
•
Each VLAN map consists of a series of entries. The order of entries in an VLAN map is important.
A packet that comes into the switch is tested against the first entry in the VLAN map. If it matches,
the action specified for that part of the VLAN map is taken. If there is no match, the packet is tested
against the next entry in the map.
•
If the VLAN map has at least one match clause for the type of packet (IP or MAC) and the packet
does not match any of these match clauses, the default is to drop the packet. If there is no match
clause for that type of packet in the VLAN map, the default is to forward the packet.
•
The system might take longer to boot if you have configured a very large number of ACLs.
•
For information about using both router ACLs and VLAN maps, see the
Router ACLs and VLAN Maps” section on page 28-36
•
See the
“Using VLAN Maps in Your Network” section on page 28-33
for configuration examples.
•
When a switch has an IP access list or MAC access list applied to a Layer 2 interface, you can create
VLAN maps, but you cannot apply a VLAN map to any of the switch VLANs. An error message is
generated if you attempt to do so.
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.
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 |
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.
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.