User Guide

Configuring AP access points 271
Nortel WLAN Security Switch 2300 Series Configuration Guide
that protection mode is less likely to be required. In this case, the 802.11b/g radios require a client to support
all the 802.11g rates.
To configure 802.11b/g radios to reject association attempts from 802.11b clients, use the following
command:
set radio-profile name 11g-only {enable | disable}
To configure the 802.11b/g radios in radio profile rp1 to allow associations from 802.11g clients only, type the
following command:
23x0# set radio-profile rp1 11g-only enable
success: change accepted.
Changing the Preamble Length
By default, 802.11b/g radios advertise support for frames with short preambles and can support frames with
short or long preambles.
An 802.11b/g radio generates unicast frames to send to a client with the preamble length specified by the
client. An 802.11b/g radio always uses a long preamble in beacons, probe responses, and other broadcast or
multicast traffic.
Generally, clients assume access ports require long preambles and request to use short preambles only if the
access point with which they are associated advertises support for short preambles. You can disable the adver-
tisement of support for short preambles by setting the preamble length value to long. In this case, clients
assume that the access point supports long preambles only and the clients request long preambles.
Changing the preamble length value affects only the support advertised by the radio. Regardless of the
preamble length setting (short or long), an 802.11b/g radio accepts and can generate 802.11b/g frames with
either short or long preambles.
If any client associated with an 802.11b/g radio uses long preambles for unicast traffic, the AP access point
still accepts frames with short preambles but does not transmit any frames with short preambles. This change
also occurs if the access point overhears a beacon from an 802.11b/g radio on another access point that
indicates the radio has clients that require long preambles.
The default preamble length value is short. This command does not apply to 802.11a radios.
To change the preamble length advertised by 802.11b/g radios, use the following command:
set radio-profile name preamble-length {long | short}
To configure 802.11b/g radios that use the radio profile rp_long to advertise support for long preambles
instead of short preambles, type the following command:
23x0# set radio-profile rp_long preamble-length long
success: change accepted.
Note. Even when association of 802.11b clients is disabled, if an 802.11b/g radio
detects a beacon from an 802.11b network, the radio enters protection mode to protect
against interference.