5 port identifier – Pilz PSSnet SHL 8T MRP User Manual
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Rapid Spanning Tree
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4.1 The Spanning Tree Protocol
PSSnet SHL - Redundancy Configuration
Pilz GmbH & Co. KG, Felix- Wankel Str. 2, 73760 Ostfildern
4.1.5 Port Identifier
The Port Identifier consists of 2 bytes. One part, the lowest-value byte, signi-
fies the fixed relationship with the physical port number. This part ensures
that no port of a bridge has the same identifier as another port of this bridge.
The second part is the port priority, which is specified by the Administrator
(default value: 128). It also applies here that the port with the smallest
number for the port identifier has the highest priority.
Figure 30: Port Identifier
Data rate
Recommended value
Recommended range
Possible range
<=100 KBit/s 200.000.000*
20.000.000-200.000.000 1-200.000.000
1 MBit/s
20.000.000*
2.000.000-200.000.000
1-200.000.000
10 MBit/s
2.000.000*
200.000-20.000.000
1-200.000.000
100 MBit/s
200.000*
20.000-2.000.000
1-200.000.000
1 GBit/s
20.000
2.000-200.000
1-200.000.000
10 GBit/s
2.000
200-20.000
1-200.000.000
100 GBit/s
200
20-2.000
1-200.000.000
1 TBit/s
20
2-200
1-200.000.000
10 TBit/s
2
1-20
1-200.000.000
Table 10: Recommended path costs for RSTP based on the data rate
* Bridges that conform with IEEE 802.1D, 1998 edition, and only support
16-bit values for the path costs should use the value 65 535 for path costs
when they are used in conjunction with bridges that support 32-bit values
for the path costs.
Priority Port number
MSB
LSB