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Cisco Wireless LAN Controller Configuration Guide
OL-17037-01
Chapter 1 Overview
Layer 2 and Layer 3 Operation
Layer 2 and Layer 3 Operation
Lightweight Access Point Protocol (LWAPP) communications between the controller and lightweight
access points can be conducted at ISO Data Link Layer 2 or Network Layer 3. Control and Provisioning
of Wireless Access Points protocol (CAPWAP) communications between the controller and lightweight
access points are conducted at Network Layer 3. Layer 2 mode does not support CAPWAP.
Note
Controller software release 5.2 or later supports only Layer 3 CAPWAP mode, controller software
releases 5.0 and 5.1 support only Layer 3 LWAPP mode, and controller software releases prior to 5.0
support Layer 2 or Layer 3 LWAPP mode.
Note
The IPv4 network layer protocol is supported for transport through a CAPWAP or LWAPP controller
system. IPv6 (for clients only) and Appletalk are also supported but only on 4400 series controllers and
the Cisco WiSM. Other Layer 3 protocols (such as IPX, DECnet Phase IV, OSI CLNP, and so on) and
Layer 2 (bridged) protocols (such as LAT and NetBeui) are not supported.
Operational Requirements
The requirement for Layer 3 LWAPP communications is that the controller and lightweight access points
can be connected through Layer 2 devices on the same subnet or connected through Layer 3 devices
across subnets. Another requirement is that the IP addresses of access points should be either statically
assigned or dynamically assigned through an external DHCP server.
The requirement for Layer 3 CAPWAP communications across subnets is that the controller and
lightweight access points are connected through Layer 3 devices. Another requirement is that the IP
addresses of access points should be either statically assigned or dynamically assigned through an
external DHCP server.
Configuration Requirements
When you are operating the Cisco Wireless LAN Solution in Layer 2 mode, you must configure a
management interface to control your Layer 2 communications.
When you are operating the Cisco Wireless LAN Solution in Layer 3 mode, you must configure an
AP-manager interface to control lightweight access points and a management interface as configured for
Layer 2 mode.
Cisco Wireless LAN Controllers
When you are adding lightweight access points to a multiple Cisco Wireless LAN Controller
deployments network, it is convenient to have all lightweight access points associate with one master
controller on the same subnet. That way, the operator does not have to log into multiple controllers to
find out which controller newly-added lightweight access points associated with.
