Port Identifier - Hirschmann RS40 User Manual

Rapid Spanning Tree
Data rate Recommended value
<=100 KBit/s 200 000 000*
1 MBit/s 20 000 000*
10 MBit/s 2 000 000*
100 MBit/s 200 000*
1 GBit/s 20 000
10 GBit/s 2 000
100 GBit/s 200
1 TBit/s 20
10 TBit/s 2
Table 11: 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.

4.1.5 Port Identifier

The Port Identifier consists of 2 bytes. One part, the lowest-value byte,
signifies 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 number, which is specified by the
Management Administrator (default value: 128). It also applies here that the
port with the smallest number for the port identifier has the highest priority.
MSB LSB
Priority Port number
Figure 29: Port Identifier
Redundancy L2E
Release 4.1 03/08
4.1 The Spanning Tree Protocol
Recommended range
20 000 000-200 000 000 1-200 000 000
2 000 000-200 000 000
200 000-20 000 000
20 000-2 000 000
2 000-200 000
200-20 000
20-2 000
2-200
1-20
Possible range
1-200 000 000
1-200 000 000
1-200 000 000
1-200 000 000
1-200 000 000
1-200 000 000
1-200 000 000
1-200 000 000
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