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not require IP address configuration (they inherit the IP address of the standard wireless
interface), they can be configured to automatically connect to other WDS enabled Access
Points.
A WDS router interface allows traffic to be routed to an Access Point on a different
network, and therefore requires configuration of an IP address to reflect the network
address of the destination network. WDS router interfaces cannot provide the redundan-
cy of bridge interfaces, but can be used to reduce radio bandwidth requirements because
the router can determine the destination based on IP address, whereas the bridge must
go through a learning phase where all broadcast traffic must be retransmitted on each
interface. Routed networks may also be used in some cases to avoid the overhead intro-
duced by the bridge Spanning Tree Protocol when network loops exist.
In the above example, 4 Access Points (A, B, C, and D) form a mesh network using only
WDS bridge interfaces. Each of the Access Points may also have its own clients associ-
ated. A, B, C, and D can all exchange data with each other (as can all of their clients) as if
they were all on the same wired segment. It can bee seen that there are redundant paths
and also the possibility for loops to occur, so that the bridge Spanning Tree Protocol
should be enabled. To illustrate the redundancy, consider that if A needs to send data to
D it has redundant paths through both B and C. However, due to the spanning tree pro-
tocol only one of B or C will relay the data, with the other taking over in the event of a
failure.
The configuration for unit A from the WDS bridge example is shown below (this page is
accessible via the
Repeaters
link from the configuration web pages). It can be seen that
“WDS” mode and “Bridge Spanning Tree Protocol” are enabled, and “Auto Connect to
WDS enabled AP’s” is selected. Note that auto connect mode requires that none of the
Access Points disable their “SSID broadcast”, otherwise they must have the same SSID. If
this is not the case the connections must be manually entered into the WDS connection
list (described later). The WDS configurations for units B, C, and D are identical to A.
An example of using WDS router interfaces to achieve a similar physical topology to
the WDS bridge example discussed earlier is illustrated below. In both examples, there
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