Allied Telesis Rapier i AT-RP16Fi/SC, Руководство пользователя

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Layer 2 Switching 91
Software Release 2.6.1
C613-02025-00 REV C
To specify whether the STP will operate in STANDARD mode or RAPID mode,
use the command:
SET STP={ stp-name |ALL} [MODE={STANDARD|RAPID}] [ other
parameters ]
The default is STANDARD. If the mode is changed while the algorithm is
running then the STP is re-initialised.
To display the STP state of the switch ports (Figure 21 on page 98), use the
command:
SHOW STP[={stp-name|ALL}] PORT={port-list|ALL}
A Rapier switch in default LAN configuration has a default Spanning Tree
enabled, spanning only a single default VLAN, to which all ports belong. The
switches in the LAN run a distributed Spanning Tree Algorithm to create a
single Spanning Tree. In a network of Rapier switches with VLANs configured,
all VLANs belong by default to a default Spanning Tree called
default . Multiple
Spanning Trees can be created with each Spanning Tree encompassing multiple
VLANs (in networks switched exclusively by Rapier switches).
For more information about multiple spanning trees, see the Switching chapter
in the Rapier Switch Software Reference .
Overlapping VLANs belonging to multiple Spanning
Tree instances
The Rapier i Series switches support the situation where a port is contained in
more than one Spanning Tree instance when the port is a member of more than
one VLAN and those VLANs belong to different STPs (See Figure 19 on
page 91). On the Rapier
i Series switches only, the number of STPs that can be
configured is 255.
Figure 19: Port membership of VLANs which belong to different spanning tree instances (on Rapier i Series
switches only).
STP A
STP B
VLAN 1
VLAN 2
VLAN 3
Port 1
Port 2
Port 3
Port 2 is a member of multiple Spanning Tree Instances (STP A and STP B) because it is a member of
multiple VLANs (VLAN 2 and VLAN 3).
SWITCH12