BelAir Networks BelAir 100SN, Руководство пользователя

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BelAir100SN User Guide Layer 2 Network Configuration
May 31, 2010 Confidential Page 178 of 212
Document Number BDTM11001-A01 Released
RSTP Static Path Cost
/protocol/rstp/set interface <interface-name>
defaultcost <1 - 200000000>
This command sets the static path cost in the
pathcost
field. This command is
available only if dynamic path costs are disabled. Refer to “Dynamic Path Cost”
on page 178 .
The
<interface-name>
parameter specifies a particular interface, such as
wifi-2-1
.
The static path cost determines the preferred data paths between bridges
throughout the network and the root bridge. The default path cost settings
vary, depending on the hardware in use, the topology and whether dynamic
path cost is used or not.
Example
/protocol/rstp# set interface wifi-2-1 pathcost 65535
Dynamic Path Cost
/protocol/rstp/set interface <interface-name>
[dynamic-cost {enabled|disabled}]
This command lets you manage how path costs are determined for each radio
link on your BelAir100SN.
The
<interface-name>
parameter specifies a particular interface, such as
wifi-2-1
.
Dynamic path costs are a useful way to adjust the topology of a network to
isolate a link as a result of unplanned or seasonal effects. For example, there
may be an unplanned source of radio interference with a particular link. Or,
vegetation may affect a link during summer.
When dynamic cost is disabled, each link is assigned a fixed cost. The default
value depends on the hardware and topology in use.
When dynamic cost is enabled, the BelAir100SN adjusts the link’s cost based
on several link quality factors. For example, a link with a low RSSI, such as -80,
implies poor link quality causing it to have an increased cost. Similarly, a link
with a high RSSI, such as -40, implies good link quality causing it’s cost to be
reduced.
Enabling dynamic path costs disables the command to configure a static path
cost. Refer to
“RSTP Static Path Cost” on page 178 .
To prevent unnecessary topology changes based on transient behaviour, a new
link cost may not automatically cause a topology change. If the new link cost is