Figure 6-4 Scenario where PIDs need to be compared
S1
S2
A
B
designated port
blocked port
Five Port States
Table 6-4 describes the possible states of ports on an STP device.
Table 6-4 STP port states
Port
State
Purpose Description
Forwardi
ng
A port in Forwarding state can forward
user traffic and process BPDUs.
Only the root port and designated port
can enter the Forwarding state.
Learning When a port is in Learning state, the
device creates MAC address entries
based on user traffic received on the
port but does not forward user traffic
through the port.
This is a transitional state, which is
designed to prevent temporary loops.
Listening All ports are in Listening state before
the root bridge, root port, and
designated port are selected.
This is a transitional state.
Blocking A port in Blocking state receives and
forwards only BPDUs, and does not
forward user traffic.
This is the final state of a blocked port.
Disabled A port in Disabled state does not
process BPDUs or forward user traffic.
The port is Down.
Figure 6-5 shows the state transitions of a port.
Huawei AR530&AR550 Series Industrial Switch Routers
Configuration Guide - Ethernet Switching
6 STP/RSTP Configuration
Issue 01 (2014-11-30) Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
168
To Next Page
Loading...
