Cisco Catalyst 2960 Series, Configuration Manual

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• 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.
• Logging is not supported for VLAN maps.
• When a switch has an IP access list or MAC access list applied to a Layer 2 interface, and you apply a
VLAN map to a VLAN that the port belongs to, the port ACL takes precedence over the VLAN map.
• If a VLAN map configuration cannot be applied in hardware, all packets in that VLAN are dropped.
VLAN Maps with Router ACLs
To access control both bridged and routed traffic, you can use VLAN maps only or a combination of router
ACLs and VLAN maps. You can define router ACLs on both input and output routed VLAN interfaces, and
you can define a VLAN map to access control the bridged traffic.
If a packet flow matches a VLAN-map deny clause in the ACL, regardless of the router ACL configuration,
the packet flow is denied.
When you use router ACLs with VLAN maps, packets that require logging on the router ACLs are not
logged if they are denied by a VLAN map.
Note
If the VLAN map has a match clause for the type of packet (IP or MAC) and the packet does not match the
type, the default is to drop the packet. If there is no match clause in the VLAN map, and no action specified,
the packet is forwarded if it does not match any VLAN map entry.
VLAN Maps and Router ACL Configuration Guidelines
These guidelines are for configurations where you need to have an router ACL and a VLAN map on the same
VLAN. These guidelines do not apply to configurations where you are mapping router ACLs and VLAN
maps on different VLANs.
If you must configure a router ACL and a VLAN map on the same VLAN, use these guidelines for both router
ACL and VLAN map configuration:
• You can configure only one VLAN map and one router ACL in each direction (input/output) on a VLAN
interface.
• Whenever possible, try to write the ACL with all entries having a single action except for the final,
default action of the other type. That is, write the ACL using one of these two forms:
permit... permit... permit... deny ip any any
or
deny... deny... deny... permit ip any any
• To define multiple actions in an ACL (permit, deny), group each action type together to reduce the
number of entries.
• Avoid including Layer 4 information in an ACL; adding this information complicates the merging
process. The best merge results are obtained if the ACLs are filtered based on IP addresses (source and
Consolidated Platform Configuration Guide, Cisco IOS Release 15.2(4)E (Catalyst 2960-X Switches)
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Information About VLAN Access Control Lists