Table of contents
WDS wireless distribution system
Configuration of Ruijie Wireless Bridge
Configuration of root bridge (thin AP is configured on AC)
Configuration of non-root bridge (configure directly on AP)
WDS wireless distribution system
WDS refers to connecting two or more independent local area networks (wired and wireless) between APs through wireless links; so as to achieve the function of connecting distributed networks and expanding wireless signals
In some scenarios, it is difficult/costly to deploy APs through wired connections, and wireless bridge (WDS) technology will be used to save costs.
WDS role
WDS mainly has two roles: root bridge and non-root bridge.
Among them, the root bridge and the non-root bridge are not for the AP, but for the radio frequency card (that is, an AP can be the root bridge and the non-root bridge at the same time)
The root bridge sends signals, and the non-root bridge connects the signals sent by the root bridge to establish a wireless link (equivalent to the root bridge transmitting signals, and the non-root bridge being the terminal)
The wireless bridge must be a root bridge and a non-root bridge for bridging, and both sides need to be configured accordingly
The principle of wireless bridging
The root bridge will designate a BSS (SSID+BSSID) for non-root bridge access to establish a bridge (the BSS does not allow ordinary STA user access)
The non-root bridge will search for a root bridge that can be accessed according to the manually configured BSSID or SSID, and apply for establishing a wireless link
After the root bridge is judged, it will perform access processing (1. Whether it is the same manufacturer device 2. Whether it is the same device chip 3. Whether it is the same password--ignore if encryption is not configured); therefore, it is generally recommended to use devices of the same model for bridging
Wireless bridge establishes message exchange
1. The non-root bridge carries the manually configured SSID/BSSID of the root bridge to make a detection request
2. Genqiao responds after receiving
3. The non-root bridge sends an authentication request
4. The root bridge judges based on whether the WDS whitelist is configured
If the whitelist is not enabled, allow this non-root bridge to access
If the whitelist is enabled, only the non-root bridge in this whitelist will allow the non-root bridge to access
5. The non-root bridge performs operations such as association and access authentication after receiving the authentication response from the root bridge
Wireless Bridging Considerations
It is necessary to pay attention to whether the signal of the root bridge can cover the non-root bridge (generally, the height difference between the root bridge and the non-root bridge is less than 20 meters, and the signal of the root bridge can be sent to the non-root bridge vertically and horizontally; if the height difference is 20m~50m, Then the root bridge needs to go down about 10 degrees to the non-root bridge to make a signal)
Generally use 5.8G signal for bridging; use 2.4G for bridging interference is relatively large
Generally, outdoor bridging is recommended; indoor bridging has a lot of interference, and the flow of people is large, which is easy to block the signal
Generally, a directional antenna is used for bridging (the distance of the external directional antenna is longer)
It is necessary to pay attention to the risk of hidden nodes; if the distance between the remote non-root bridges is relatively long, and they cannot hear each other, it may cause conflicts in sending data; generally ensure that the RSSI value on the non-root bridge, that is, the signal strength is greater than -25dBm, Generally, the hidden node problem can be ignored
To avoid the risk of channel interference
WDS networking topology
WDS supports relay bridging, one-to-one bridging, one-to-many bridging, multi-hop bridging
Among them, the relay bridge is mainly to amplify the signal, and the rest of the bridge is mainly to connect the distributed network.
relay bridging
Amplify the signal through the repeater and use it for distant terminals
Among them, the repeater does not need to be configured like the AP, but only plays the role of amplifying the signal
So repeaters can be devices from different manufacturers
one-to-one bridging
AP2 acts as the root bridge; AP1 acts as the non-root bridge for wireless bridging
AP1 receives the signal sent by AP2, establishes a wireless link, and realizes wireless access of users under AP1
one-to-many bridging
One root bridge to multiple non-root bridges
AP4 sends signals as the root bridge, and AP1, AR2, and AP3 connect to the root bridge as non-root bridges to establish wireless links to realize wireless access for STA users under it.
Precautions
A root bridge can connect to multiple non-root bridges; a non-root bridge can only connect to one root bridge
Under normal circumstances, a root bridge can connect 32 non-root bridges. If the distance is far, the risk of using one-to-many is greater
It is not recommended to have more than 5 for actual deployment, and no more than 8 at most
multi-hop bridging
Implementation principle of multi-hop bridging (equivalent to using 2 WDS networking)
That is, the distance between the root bridge and the non-root bridge is too far (greater than 3km), and the non-root bridge cannot directly find the signal of the root bridge. At this time, a transfer point can be made on both sides of the root bridge and the non-root bridge; Non-root bridge composition
The non-root bridge on the transfer point establishes a wireless link with the remote root bridge, and the root bridge on the transfer point establishes a wireless link with the remote non-root bridge; connect them
Since a non-root bridge can only be connected to one root bridge at the same time, the root bridge and non-root bridge can only be connected by wire at the transit point.
Precautions for multi-hop bridging
If there is an obstacle between the root bridge and the non-root bridge, you can also use multi-hop to avoid it
In multiple bridging scenarios, the root bridge and non-root bridge are generally bridged through BSSID (if SSID bridging is used, it may cause a loop)
It is also recommended to use BSSID bridging in scenarios with many root bridges (to prevent wrong connection of non-root bridges)
In scenarios with many non-root bridges and few root bridges, SSID is generally used (when there is a problem with the root bridge, replace it with a new device, issue the same SSID, and the non-root bridge can be connected; needs to be changed)
Configuration of Ruijie Wireless Bridge
Configuration of root bridge (thin AP is configured on AC)
The following only introduces the configuration of the wireless signal used for non-root bridge access. For the STA user access signal under the root bridge, you only need to create a new Wlan ID and bind the wlan id and radio under the AP group; if the STA The address is assigned by the AC, and the configuration method is the same as that of the root bridge to assign addresses to non-root bridges.
Start WDS mode
wds-mode enable At this time, Hugo has configured the root bridge and the non-root bridge, and they will restart
Create a wireless signal to bridge the AP (SSID is root1)
wlan-config 1 root1
tunnel local
Create the IP address and address pool used by the bridge AP
vlan 100
int vlan 100
ip add 10.0.0.254 24
ip dhcp pool ap
network 10.0.0.0 255.255.255.0
default-router 10.0.0.254
option 138 ip 10.10.10.10 specifies the address of the AC
service dhcp
Create an AP group
ap-group root1
interface-mapping 1 100 radio2 bind vlan100 and wlan-id 1 to radio2 (5G radio frequency)
Add the bridge AP to the corresponding group
ap-config ap-root
ap-mac 0000.0001.0001
ap-group root1
station-role root-bridge-wlan 1 radio 2 Configure AP's radio2 for wireless bridging
bridge-wlan 1 refers to the first mapping of the bridged Wlan under the AP group to which the AP belongs (can be viewed through show run) In fact, we only need to pay attention to this command
Configuration of non-root bridge (configure directly on AP)
Connecting a non-root bridge to a root bridge
int dott11rdio 2/0 enter radio frequency card 2
station-role non-root-bridge Configure interface mode as non-root bridge
parent ssid root1 Configure the SSID of the root bridge
parent mac-address 0000.0001.0001 Configure the BSSID of the root bridge
wds pre-config cerate generate Wds pre-configuration file
A non-root bridge creates a signal for STA access
Same as the normal thin AP configuration, it can be configured directly on the AC wireless controller