D-Link DES-3624 - Switch - Stackable User manual - Illustration of Sta

Stackable NWay Ethernet Switch User’s Guide 

Illustration of STA 

A simple illustration of three Bridges (or the Switch) connected 

in a loop is depicted in Figure  5-1. In this example, you can 

anticipate some major network problems if the STA assistance 

is not applied. For instance, if Bridge 1 broadcasts a packet to 

Bridge 2, Bridge 2 will broadcast it to Bridge 3, and Bridge 3 

will broadcast it to Bridge 1 and so on. The broadcast packet 

will be passed indefinitely in a loop, causing a serious network 

failure. 

To alleviate network loop problems, STA can be applied as 

shown in Figure 5-2. In this example, STA breaks the loop by 

blocking the connection between Bridge 1 and 2. The decision 

to block a particular connection is based on the STA 

calculation of the most current Bridge and Port settings. Now, 

if Bridge 1 broadcasts a packet to Bridge 3, then Bridge 3 will 

broadcast it to Bridge 2 and the broadcast will end there. 

STA setup can be somewhat complex. Therefore, you are 

advised to keep the default factory settings and STA will 

automatically assign root bridges/ports and block loop 

connections. However, if you need to customize the STA 

parameters, refer to Table 5-1. 

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Switch Management Concepts