Configuring VLANs on AP1200

[ricardo.marin]

I want to configure a VLAN through our CISCO AIRONET 1200 Access Point. In order to do this, we have read the Installation and Configuration Guide and we have found that the mechanism includes the assignment the VLAN to an SSID and also the encapsulation of the packets that arrive to a determined sub-interface assigning the VLANId to this encapsulation.

What is exactly a sub-interface? Which is the criteria to assign a determined sub-interface to a VLAN? The second question is related to the fact that in the Configuration Guide says how to assign it, but it does not establish a criterium to choose the number of the sub-interface. Finally, why is this assignment between sub-interface and VLANId neccessary?.

[rmiles]

When you create the VLAN on the access point it will automatically create the sub interface. If you create lets say VLAN 80, the access point will create a .80 subinterface for the ethernet side and the radio side. Each VLAN must use a unique SSID. When you create VLANs the access point will convert the ethernet interface to a dot1q trunk. Make sure your switch port connecting to the access point is also set as a trunk.

[emcpherson]

Don't forget the Native Vlan. Very important. Better yet assign a different VLAN ID from the default ID "1" so that you have a different native VLAN than your switch's default native vlan.