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Catalyst 3750 SwitchSoftware Configuration Guide
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AppendixA Configuring the Catalyst 3750G Integrated Wireless LAN Controller Switch
Understanding the Wireless LAN Controller Switch
Understanding the Wireless LAN Controller Switch
The Catalyst 3750G Integrated Wireless LAN Controller Switch is a Layer 3 IEEE 802.3af-compliant
switch with an integrated wireless LAN controller capable of supporting up to 25 or 50 lightweight
access points. The switch combines the Catalyst 3750 switch infrastructure with wireless LAN controller
and access points to provide an IEEE 802.11 mobile wireless solution.
The wireless LAN controller switch has these features:
•Layer 2 and Layer 3 wireless mobility
•wireless LAN controller in appliance mode using Layer 3 Lightweight Access Point Protocol
(LWAPP) to control access points in the same or different subnet than the controller
•Layer 3 roaming
•single point of ingress for wireless traffic
•integration of wireless traffic with existing wired network infrastructure.
•Layer 2 switching and Layer 3 routing capability
•software parity with the Catalyst 3750 IP base and IP services cryptographic and noncryptographic
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•optimized for 25 and 50 access points and up to 500 wireless users
•Power over Ethernet ports for powering access points or other network appliances, such as IP phones
The Catalyst 3750G switch software handles all the switch features, including routing, bridging, access
control lists (ACLs), and quality of service (QoS). The controller handles all wireless functionality. The
Catalyst 3750G switch and the internal wireless controller are connected internally through two Gigabit
Ethernet links. These links are automatically configured to direct the switch wireless traffic toward the
controller, requiring minimal configuration by the user.

The Wireless LAN Controller Switch and Switch Stacks

The wireless LAN controller switch can coexist with other Catalyst 3750 switches in a switch stack.
However, for controller functionality, all switches in the stack should be running software that supports
the controller. To support wireless controller redundancy, there should be at least two wireless LAN
controller switches in a stack. A stack should contain no more than four wireless LAN controller
switches.
The wireless LAN controller switch can be a master switch or a member switch in a stack. Stacking
behavior for a wireless LAN controller switch is consistent with that of other Catalyst 3750 switches.
For wireless functionality, you can configure the access points so that if one wireless LAN controller
switch in a stack shuts down, the access points and wireless clients controlled by the controller in this
switch automatically migrate to the controller of another wireless LAN controller switch in the stack,
The traffic for wireless clients experiences a short interruption due to reassociation and reauthentication.
In a switch stack, each switch holds a unique switch number (1 to 9). This same switch number is used
to access the controller in a switch in a stack or a standalone switch, where the switch number is 1 by
default. For example, to access the controller in stack member 3, use the session 3 processor 1 privileged
EXEC command (where processor 1 represents the controller). To access the controller in a standalone
switch, use the command session 1 processor 1.
Note Always power off a switch before adding or removing it from a switch stack.