Cisco Cisco 2106 Wireless LAN Controller
9
Release Notes for Cisco Wireless LAN Controllers and Mesh Access Points for Release 4.0.217.204
OL-31336-01
Important Notes
Note
•
While traffic is moved to a new channel, the MAPs remain connected to the controller but
transmissions on the network are silent for one minute in keeping with the DFS standard.
Transmission resumes after the minute silence on the new channel.
transmissions on the network are silent for one minute in keeping with the DFS standard.
Transmission resumes after the minute silence on the new channel.
•
If a MAP detects radar immediately after the first detection, the MAPs in the sector disconnect from
the controller.
the controller.
•
If a MAP is connected to a RAP with a default bridge group name (BGN), the MAP does not relay
the radar detection message to the RAP.
the radar detection message to the RAP.
Dynamic Frequency Selection Added to Access Points in -A Regulatory Domain
In controller software release 4.2.99.0, dynamic frequency selection (DFS) is enabled automatically on
the following Cisco lightweight access points that are configured for use in the -A regulatory domain
(U.S., Canada, and Philippines): 1130, 1230, and 1240. DFS affects 8 channels (52 to 64) on the 802.11a
radio within the 5.470 to 5.725 GHz frequency band. The access points use DFS to detect radar signals
such as military and weather sources and then switch channels to avoid interfering with them.
the following Cisco lightweight access points that are configured for use in the -A regulatory domain
(U.S., Canada, and Philippines): 1130, 1230, and 1240. DFS affects 8 channels (52 to 64) on the 802.11a
radio within the 5.470 to 5.725 GHz frequency band. The access points use DFS to detect radar signals
such as military and weather sources and then switch channels to avoid interfering with them.
DHCP Bridging
You can enable or disable the DHCP Proxy functionality on a controller. This feature is either enabled
or disabled on a global basis rather than on a WLAN-by-WLAN basis using the following command:
or disabled on a global basis rather than on a WLAN-by-WLAN basis using the following command:
config dhcp proxy {enable | disable}
Note
DHCP Proxy is enabled by default. All controllers that will communicate must have the same DHCP
Proxy setting.
Proxy setting.
When DHCP Proxy is enabled on a controller, the controller unicasts DHCP requests from the client to
the configured servers. Consequently, at least one DHCP server must be configured on either the
interface associated with the WLAN or the WLAN itself.
the configured servers. Consequently, at least one DHCP server must be configured on either the
interface associated with the WLAN or the WLAN itself.
When DHCP Proxy is disabled on a controller, those DHCP packets transmitted to and from the clients
are bridged by the controller without any modification to the IP portion of the packet. Packets received
from the client are removed from the LWAPP tunnel and transmitted on the upstream VLAN. DHCP
packets directed to the client are received on the upstream VLAN, converted to 802.11 packets and
transmitted through an LWAPP tunnel toward the client. As a result, the internal DHCP server cannot be
used when the DHCP Proxy is disabled.
are bridged by the controller without any modification to the IP portion of the packet. Packets received
from the client are removed from the LWAPP tunnel and transmitted on the upstream VLAN. DHCP
packets directed to the client are received on the upstream VLAN, converted to 802.11 packets and
transmitted through an LWAPP tunnel toward the client. As a result, the internal DHCP server cannot be
used when the DHCP Proxy is disabled.
Note
In earlier releases, disabling DHCP Proxy only changed how the attributes were inserted and removed
from the DHCP packets. Packets were still proxied by the controller to the configured DHCP servers.
from the DHCP packets. Packets were still proxied by the controller to the configured DHCP servers.