Spanning Tree Considerations For Multilink Trunks; Figure 39 Path Cost Arbitration Example - Nortel BayStack 380 Using Manual

Spanning tree considerations for MultiLink Trunks

The spanning tree Path Cost parameter is recalculated based on the aggregate
bandwidth of the trunk. For example,
two port members operating at an aggregate bandwidth of 2.2 Gb/s, with a
comparable Path Cost of 4. When the Path Cost calculations for both trunks are
equal, the software chooses the trunk with the larger aggregate bandwidth (T1) to
determine the most efficient path.

Figure 39 Path Cost arbitration example

S1
1000 Mb/s
Path Cost T1 = 1
1000 Mb/s
Aggregate Bandwidth
2 Gb/s
S2
Figure 39
T1 T2
Using the BayStack 380 10/100/1000 Switch
Chapter 2 Network configuration
shows a four-port trunk (T1) with
BayStack
380
100 Mb/s
Path Cost T2 = 5
100 Mb/s
Aggregate Bandwidth
200 Mb/s
BayStack
380
87
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