Administrator Guide

Table Of Contents
742 VLANs
Configuring MAC-Based VLANs
Beginning in Privileged EXEC mode, use the following commands to
associate a MAC address with a configured VLAN. The VLAN does not need
to be configured on the system to associate a MAC address with it. However,
the associated VLAN must be configured on a port in order for the system to
map packets matching the MAC address to the associated VLAN and to learn
the associated MAC address on the associated VLAN so that packets
addressed to the associated MAC address are forwarded properly. Up to 256
VLAN to MAC address associations can be created. VLAN associations
operate on untagged packets on access and trunk ports. Tagged traffic is
associated with the VLAN identified in the VLAN tag.
switchport trunk allowed
vlan 100
Only allow VLAN 100 packets on the interface.
switchport trunk native
vlan 100
Configure untagged packets to be members of VLAN 100.
Command Purpose
configure Enter global configuration mode.
interface gi1/0/3 Enter Interface Config mode for port gil/0/3.
switchport mode trunk Configure gi1/0/3 as a trunk port associated with the
selected VLAN ID.
Note that the native VLAN for gi1/0/3 is still VLAN 1.
Untagged traffic with the associated MAC address is
learned on the associated VLAN ID, not VLAN 1.
exit Exit to Global Config mode.
interface gi1/0/4 Enter Interface Config mode for port gi1/0/4.
switchport access vlan
vlanid
Configure gi1/0/4 as an access port.
The PVID for Gi1/0/4 is the associated VLAN ID. It will
receive the MAC associated traffic.
exit Exit to Global Config mode.
vlan
vlanid
Enter VLAN configuration mode.
Command Purpose