LAN-to-LAN Configuration
1-12
In Figure1-4, Building A is the Central AP for Buildings A1 through A5 and Building
B. However, Building B is also the Central AP for Building A and Buildings B1
through B5. You could expand this one further by making Building B3 a Central AP
for five other buildings, although adding additional hops may decrease network
performance.
To avoid bridging problems, do not configure an AP as an Endpoint for more than on e
Central AP. In Figure1-4, you would not configure Building B1 as an Endpoint to
communicate directly to Building A.
Preventing Network Loops
It is important to avoid Point-to-Multipoint configurations that will cause bridge loops. A
bridge loop occurs when two parallel network paths are created between any two LANs,
causing packets to be continuously regenerated through both parallel paths. This situation
eventually renders the network unusable due to the excessive traffic that is being generated
by the loop. The AP Spanning Tree function corrects this type of problem by shutting down
the port and possibly shutting down a segment of the network.
Figure1-5 provides examples of configurations that cause Network Loops.
Figure 1-5: Network Loops
Building A
Multipoint Mode
Building C
Multipoint Mode
Building B
Multipoint Mode Building B
Endpoint Mode
Wired or Fiber Link
Building C
Endpoint Mode
Building A
Multipoint Mode
(Central AP)