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Valid priority values are 0, 4096, 8192, 12288, 16384, 20480, 24576, 28672, 32768, 36864, 40960, 45056, 49152,
53248, 57344, and 61440. All other values are rejected.
To return the switch to its default setting, use the
no spanning-tree priority
configuration command.
Restarting the Protocol Migration Process
A switch when running RSTP supports a built-in protocol migration mechanism that enables it to interoperate with
legacy 802.1D switches. If this switch receives a legacy 802.1D configuration BPDU (a BPDU with the protocol
version set to 0), it sends only 802.1D BPDUs on that port. To restart the protocol migration process (force the re-
negotiation with neighboring switches) on the entire switch, you can use the
clear spanning-tree detected-
protocols
enable mode
command. Use the
clear spanning-tree detected-protocols interface
interface-id
enable
mode command to restart the protocol migration process on a specific interface.
Configuring Link Type
Use the following interface mode command to configure port link-type:
Router(config)#
interface eth1
Router(config-if-eth1)#
spanning-tree link-type
{
point-to-point
|
shared
}
By default, the link type is determined from the duplex mode of the interface: a full-duplex port is considered to have a
point-to-point connection; a half-duplex port is considered to have a shared connection.
To return the switch to its default setting, use the
no spanning-tree link-type
interface configuration command.
Configuring an Edge Port
Use the following interface mode command to configure port link type:
Router(config)#
interface eth1
Router(config-if-eth1)#
spanning-tree edge-port
The default setting is no edge port configuration.
To return the switch to its default setting, use the
no spanning-tree edge-port
interface configuration command.
Configuring Port Path Cost
Use the following interface mode command to configure port path cost:
Router(config)#
interface eth1
Router(config-if-eth1)#
spanning-tree path-cost
<
path-cost
>
The default values for path cost is determined by the operating port speed:
•
For ports operating in 1000Mb speed, the path cost is 20000
•
For ports operating in 100Mb speed, the path cost is 200000
•
For ports operating in 10Mb speed, the path cost is 2000000
To return the switch to its default setting, use the
no spanning-tree path-cost
interface configuration command.
