Weidmuller Wireless Ethernet Modem & Device Server WI-MOD-E-G/A User Manual
Rev.
2.16
www.weidmuller.com
55
Example 3 – Adding Redundancy
In the example below, 4 x Access Points (A, B, C, & D) form a mesh network using only WDS bridge interfaces. Each of
the Access Points may also have its own clients associated. Each Access Point is configured with a different SSID,
meaning the clients associated with each Access Point are fixed.
Figure 45 - WDS Redundancy
Sites A, B, C, and D can all exchange data with each other (as can all of their Stations) as if they were all on the same
wired segment. It can be seen that there are redundant paths and therefore the possibility for loops to occur, so the bridge
Spanning Tree Protocol should be enabled and depending on the size of the mesh possibly configuring a Bridge Priority.
Bridge Priority is used to determine the connection priority when selecting an interface to put into the forwarding state.
You can assign higher priority values to interfaces that you want spanning tree to select first and lower priority values to
interfaces that you want spanning tree to select last. If all interfaces have the same priority value, the MAC address is
used to work out the priority.
To illustrate the redundancy, consider that if Site A needs to send data to Site D it has redundant paths through both B
and C. However, due to the spanning tree protocol only one of B or C will relay the data, with the other taking over in the
event of a failure.
In this example, Site B uses its primary access point to act as an access point for Virtual Stations on Site A and D, and
uses a Virtual Station to act as a client to Site C. Sites A & D use two Virtual Stations to act as clients to Site B and to Site
C. The configuration for Site B and A & D are shown below.
Figure 46 - Site B WDS configuration
Figure 47 - Site A&D WDS configuration
Encryption levels and key above are shows as being different however they can be the same as in some of the earlier
examples. One reason why the Encryption level and key would be different is because the Access Point may have clients
