Cisco Cisco Aironet 1130 AG Access Point 릴리즈 노트
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Release Notes for Cisco Aironet Access Points for Cisco IOS Release 12.3(8)JEA
OL-11186-01
Documentation Updates
DFS Automatically Enabled on Some 5-GHz Radio Channels in North America
Access points with 5-GHz radios configured at the factory for use in North America now comply with
regulations that require radio devices to use Dynamic Frequency Selection (DFS) to detect radar signals
and avoid interfering with them.
regulations that require radio devices to use Dynamic Frequency Selection (DFS) to detect radar signals
and avoid interfering with them.
By default, the access point automatically uses DFS to set the operating frequency on 5-GHz radios. The
access point randomly selects a frequency from among these frequencies:
access point randomly selects a frequency from among these frequencies:
•
Frequencies 5.150 to 5.250 GHz (also known as the UNII-1 band)
•
Frequencies 5.250 to 5.350 GHz (also known as the UNII-2 band)
•
Frequencies 5.470 to 5.725 GHz (also known as the UNII-3 band)
•
Frequencies 5.725 to 5.825 GHz (also known as the UNII-4 band)
Note
By default, Band 3 (5.470 to 5.725 GHz) is disabled to allow backward compatibility with older clients.
You must explicitly enable it in the Radio Settings page of the GUI or by using the dfs band block radio
interface CLI command.
You must explicitly enable it in the Radio Settings page of the GUI or by using the dfs band block radio
interface CLI command.
When DFS is enabled, the access point monitors its operating frequency for radar signals. If it detects
radar signals on the channel, the access point takes these steps:
radar signals on the channel, the access point takes these steps:
•
Blocks new transmissions on the channel.
•
Flushes the power-save client queues.
•
Broadcasts an 802.11h channel-switch announcement.
•
Disassociates remaining client devices.
•
If participating in WDS, sends a DFS notification to the active WDS device that it is leaving the
frequency.
frequency.
•
Randomly selects a different 5-GHz channel.
•
Scans the new channel for radar signals for 60 seconds.
•
If there are no radar signals on the new channel, enables beacons and accepts client associations.
•
If participating in WDS, sends a DFS notification of its new operating frequency to the active WDS
device.
device.
Blocking Channels from DFS Selection
You can block groups of channels to prevent the access point from selecting them when DFS is enabled.
Use this configuration interface command to block groups of channels from DFS selection:
Use this configuration interface command to block groups of channels from DFS selection:
[no] dfs band [1] [2] [3] [4] block
The 1, 2, 3, and 4 options designate blocks of channels:
•
1—Specifies frequencies 5.150 to 5.250 GHz. This group of frequencies is also known as the UNII-1
band.
band.
•
2—Specifies frequencies 5.250 to 5.350 GHz. This group of frequencies is also known as the UNII-2
band.
band.
•
3—Specifies frequencies 5.470 to 5.725 GHz. By default, this group of channels is blocked from
DFS selection.
DFS selection.
•
4—Specifies frequencies 5.725 to 5.825 GHz. This group of frequencies is also known as the UNII-3
band.
band.