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Cooper Bussmann BU-245U-E Wireless Ethernet & Device Server User Manual
Example – WDS Routed Network
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 are four WDS Access points each with the possibility of having their own client/stations associated.In both examples A, B,
C, and D can all exchange data with each other.The bridged example has the advantage of redundancy but at the expense of extra overhead. The
routed example below cannot provide the redundancy of the bridged example, and requires more configuration effort,but does not have the
overhead of using the bridge Spanning Tree Protocol,so is suited to fixed installations that do not require redundancy.
As mentioned previously,configuration of the WDS router example is more complex than the bridged example given earlier. Each Modem and each
link have a different SSID.This is done to limit broadcast traffic and to route data only were it needs to go.
Site B in the WDS router example above has three WDS links – to Site A,C, and D; we show Site B’s configuration below. It can be seen that
there are 3 entries in the WDS Connections list.
• The first entry specifies a connection from Site B to the virtual AP at Site A whose SSID is “SSID_AA”, and has a separate Router IP address of
169.254.0.3 (this is the address that Site B adopts for the link to Site A).Note that this IP Address specifies a different network than that of the
default interface for Site A or B (i.e.,default interfaces 192.168.0.X and 192.168.X respectively). It is a requirement that the virtual interfaces at
each end-point of a WDS link have the same network structure; this ensures that the WDS links at either end point are not bridged with their
default interface.
• The second WDS entry above specifies a WDS link from Site B to the virtual Client at Site C whose SSID is “SSID_BB” and like the WDS link to
Site A uses a different Router IP address (169.254.5.X) than the default interface.Note that this network address is also different to that used
for the WDS link to Site A,so that these separate WDS interfaces are not internally bridged. In addition to adding these WDS link to Site A & C
routing rules are required to direct traffic destined for the network address of these units, i.e.,192.168.0.X & 169.254.6.X. See below for
examples routing rules.
• The third WDS entry specifies the WDS link to Site D. In the example, Site D is part of the same network structure as Site B; therefore does not
require any entries in the Router IP and Subnet fields as the BU-245U-E automatically bridges this interface with the default wireless interface.
A consequence of using a different network address for the WDS link between Sites B & A and Site B & C,is that we now need to configure
routing rules at Sites A,B and C so that the BU-245U-Es can determine where to send traffic destined for the other networks.
For example, if Site B receives traffic destined for network 192.168.0.x (i.e.,somewhere on Site A’s network), the routing rule specifies that the
traffic must be forwarded to the end point of the WDS link to Site A.The routing rules for Site B are shown below (for more information on routing
rules, refer to the section 3.14 “Routing Rules”).
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