34-31
Cisco Catalyst Blade Switch 3130 for Dell Software Configuration Guide
OL-13270-01
Chapter34 Configuring Network Securi ty with ACLs Configuring VLAN Maps
VLAN Map Configuration Guidelines
Follow these guidelines when configuring VLAN maps:
•If there is no ACL configured to deny traffic on an interface and no VLAN map is 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 up if you have configured a very l arge nu mber of ACLs.
•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 VLAN map configuration cannot be applied in hardware, all packets in that VLAN must be
bridged and routed by software.
•You can configure VLAN maps on primary and secondary VLANs. However, we recommend that
you configure the same VLAN maps on private-VLAN primary and secondary VLANs.
•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 c onfigure d
on the secondary VLAN is applied.
–
For frames going downstream from a promiscuous port to a host p ort, the VL A N ma p
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 15,
“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 Ro ut er ACL
Configuration Guidelines” section on page 34-36.