Root Path Cost - Hirschmann RS20 User Manual

Spanning Tree
5.1.4

Root Path Cost

Each path that connects 2 bridges is assigned a cost for the transmission
(path cost). The switch determines this value based on the transmission
speed (see table
transmission speeds.
Alternatively, the Administrator can set the path cost. Like the switch, the
Administrator assigns a higher path cost to paths with lower transmission
speeds. However, since the Administrator can choose this value freely, he
has a tool with which he can give a certain path an advantage among
redundant paths.
The root path cost is the sum of all individual costs of those paths that a data
packet has to traverse from a connected bridge's port to the root bridge.
Bridge 1
PC = 200 000
PC = 200 000
Bridge 2
Figure 29: Path costs
UM Redundancy Configuration L2E
Release 7.1 12/2011
11). It assigns a higher path cost to paths with lower
PC = 2 000 000
PC
Bridge 3
5.1 The Spanning Tree Protocol
Path costs
Ethernet (100 Mbit/s)
Ethernet (10 Mbit/s)
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