Extreme Networks ExtremeWare XOS 11.0, Command Reference Manual

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506 ExtremeWare XOS 11.0 Command Reference Guide
STP Commands
configure stpd ports cost
configure stpd <stpd_name> ports cost [<cost> | auto] <port_list>
Description
Specifies the path cost of the port in the specified STPD.
Syntax Description
Default
The switch automatically assigns a default path cost based on the speed of the port, as follows:
• For a 10Mbps port, the default cost is 100.
• For a 100Mbps port, the default cost is 19.
• For a 1000Mbps port, the default cost is 4.
• For a 10000Mbps ports, the default cost is 2.
The default port cost for trunked ports is dynamically calculated based on the available bandwidth.
Usage Guidelines
If your STPD has the same name as another component, for example a VLAN, Extreme Networks
recommends that you specify the identifying keyword as well as the name. If your STPD has a name
unique only to that STPD, the keyword
stpd
is optional.
You should not configure any STP parameters unless you have considerable knowledge and experience
with STP. The default STP parameters are adequate for most networks.
The range for the
cost
parameter is 1 through 65,535. The switch automatically assigns a default path
cost based on the speed of the port. If you configure the port cost, a setting of 1 indicates the highest
priority.
If you configured a port cost value and specify the
auto
option, the switch removes the user-defined
port cost value and returns to the default, automatically assigned, port cost value.
If a trunk port is the root port for an STP topology, port costs can fluctuate up and down and trigger
topology changes. For example, if all links go down in the trunk (all ports go link-down), the available
bandwidth is zero. The system displays a port cost of unknown (
Unkn
) and enters the disabled state. To
prevent this dynamic behavior, configure the port cost of the trunk port with the
configure stpd
<stpd_name> ports <cost> <port_list>
command. After you configure a static cost, the value is
frozen until you specify the
auto
option.
stpd_name Specifies an STPD name on the switch.
cost Specifies a numerical port cost value. The range is 1 through 65,535.
auto Specifies the switch to remove any user-defined port cost value(s) and use the
appropriate default port cost value(s).
port_list Specifies one or more slots and ports. May be in the form 2:*, 2:5, 2:6-2:8.