Hirschmann RS20 Programming Manual

Rapid Spanning Tree
86
6.1 The Spanning Tree Protocol
Redundanz L2P
Release 5.0 04/09
Note: If link aggregation (see on page 11 „Link Aggregation“) is used to
combine the connection lines between devices into a trunk, then the
automatically specified path costs are reduced by half.
6.1.5 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.
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 12: 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.

Hirschmann RS20 Specifications

General

Mounting	DIN Rail
Operating Temperature	-40°C to +70°C
Protection Class	IP30
Switching Technology	Store-and-Forward
Product Type	Industrial Ethernet Switch
Port Details	10/100 Mbps Ethernet ports
Switching Capacity	3.2 Gbps
MAC Address Table	8k
Management	Web, SNMP
Redundancy	MRP
Ports	8 or 16