Configuring APs 263

Nortel WLAN—Security Switch 2300 Series Configuration Guide

Resiliency and dual-homing options for APs

APs can support a wide variety of resiliency options. Redundancy for PoE, for data link connections and for WSS
services can be provided to the AP.
• PoE redundancy—On AP models that have two Ethernet ports, you can provide PoE redundancy by connecting
both ports to PoE sources. PoE can come from a directly connected WSS or a PoE injector. Dual-homing support
for PoE is automatically enabled when you connect both AP Ethernet ports.
• Data link redundancy—You can provide data link redundancy by connecting both Ethernet ports directly to one
WSS, two WSSs, an intermediate Ethernet switch, or a combination of WSS and Ethernet switch. If an intermediate
Ethernet connection is used, you also need a Distributed AP configuration on a WSS somewhere in the network.
Dual-homing support for data link redundancy is automatically enabled when you connect both AP Ethernet ports.
• WSS redundancy—You can provide redundancy of WSS services by dual-homing the AP to two directly connected
WSSs; or by configuring a Distributed AP configuration either on two or more indirectly connected WSSs, or on a
combination of a directly connected WSS and one or more indirectly connected WSSs. To provide WSS
redundancy on an AP model that has only one AP port, configure a Distributed AP connection on two or more
indirectly connected WSSs.

Bias

On a WSS, configurations for APs have a bias (low or high) associated with them. The default is high. A WSS with high
bias for an AP is preferred over a WSS with low bias for the AP.
If more than one switch has high bias, or the bias for all connections is the same, the switch that has the greatest capacity
to add more active APs is preferred. For example, if one switch has 50 active APs while another switch has 60 active
APs, and both switches are capable of managing 80 active APs, the new AP uses the switch that has only 50 active APs.
(To set the bias for an AP configuration, see “Changing bias” on page 300.)

Dual-homed configuration examples

The following sections show examples of dual-homed configurations. You can use any of these configurations to dual
home an AP model that has two Ethernet ports. AP models with one Ethernet port support only the dual-homing config-
uration in “Dual-homed distributed connections to WSSs on one AP port” on page 267.

Dual-homed direct connections to a single WSS

Figure 9 shows an example of a dual-homed direct connection to one WSS. In this configuration, if the AP’s active data
link with the WSS fails, the AP detects the link failure and restarts using the other link on the same switch.
Note. Bias applies only to WSSs that are indirectly attached to the AP through an
intermediate Layer 2 or Layer 3 network. An AP always attempts to boot on AP port 1 first,
and if a WSS is directly attached on AP port 1, the AP boots from it regardless of the bias
settings.