, deviceA and deviceB are connected through two Eth-Trunk links.
Eth-Trunk 1 has three member interfaces in Up state and Eth-Trunk 2 has two member interfaces
in Up state. Each member link has the same bandwidth, and deviceA is selected as the root
bridge.
l
Eth-Trunk 1 has higher bandwidth than Eth-Trunk 2. After STP calculation, Eth-Trunk 1
on deviceB is selected as the root port and Eth-Trunk 2 is selected as the alternate port.
l
If the maximum number of connections affecting bandwidth of Eth-Trunk 1 is set to 1, the
path cost of Eth-Trunk 1 is larger than the path cost of Eth-Trunk 2. Therefore, the two
devices perform spanning tree recalculation. Then Eth-Trunk 1 on deviceB becomes the
alternate port and Eth-Trunk 2 becomes the root port.
Figure 7-12
Setting the maximum number of connections in an Eth-Trunk
Before
configuration
After
configuration
RouterA
RouterB
Eth-Trunk1
Eth-Trunk2
Alternate port
RouterA
RouterB
Designated port
Root port
Eth-Trunk1
Eth-Trunk2
NOTE
The maximum number of connections affects only the path cost of an Eth-Trunk interface participating in
spanning tree calculation, and does not affect the actual bandwidth of the Eth-Trunk link. The actual
bandwidth for an Eth-Trunk link depends on the number of active member interfaces in the Eth-Trunk.
Procedure
Step 1
Run:
system-view
The system view is displayed.
Step 2
Run:
interface eth-trunk
trunk-id
The Eth-Trunk interface view is displayed.
Step 3
Run:
max bandwidth-affected-linknumber
link-number
The maximum number of connections affecting the Eth-Trunk bandwidth is set.
Huawei AR530&AR550 Series Industrial Switch Routers
Configuration Guide - Ethernet Switching
7 MSTP Configuration
Issue 01 (2014-11-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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