Cabletron Systems RoamAbout Access Point Manual page 24

LAN-to-LAN Configuration
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 Access Point spanning tree function corrects this type of problem by
shutting down the bridge and possibly shutting down a segment of the network.
Figure 1-5 provides examples of configurations that cause Network Loops.
Figure 1-5: Network Loops
Building B
Multipoint Mode
Building A
Multipoint Mode
1-12 Wireless Network Configurations
Building A
Building C Multipoint Mode
(Central AP)
Multipoint Mode
Building B
Endpoint Mode
Wired or Fiber Link
Building C
Endpoint Mode