If you set the link to shared, STP moves back to 802.1D.
Procedure
Purpose
Command or Action
Enters global configuration mode.
switch#
configure terminal
Step 1
Specifies the interface to configure, and enters the interface
configuration mode.
switch(config)#
interface type
slot
/
port
Step 2
If this is a 10G breakout port, the
slot
/
port
syntax is
QSFP-module
/
port
.
Note
Configures the link type to be either a point-to-point link or
shared link. The system reads the default value from the switch
switch(config-if)#
spanning-tree
link-type
{
auto
|
point-to-point
|
shared
}
Step 3
connection, as follows: half duplex links are shared and
full-duplex links are point-to-point. If the link type is shared,
the STP reverts to 802.1D. The default is auto, which sets the
link type based on the duplex setting of the interface.
This example shows how to configure the link type as a point-to-point link:
switch#
configure terminal
switch (config)#
interface ethernet 1/4
switch(config-if)#
spanning-tree link-type point-to-point
You can only apply this command to a physical Ethernet interface.
Restarting the Protocol
A bridge running Rapid PVST+ can send 802.1D BPDUs on one of its ports when it is connected to a legacy
bridge. However, the STP protocol migration cannot determine whether the legacy switch has been removed
from the link unless the legacy switch is the designated switch. You can restart the protocol negotiation (force
the renegotiation with neighboring switches) on the entire switch or on specified interfaces.
Purpose
Command
Restarts Rapid PVST+ on all interfaces on the switch
or specified interfaces.
switch#
clear spanning-tree detected-protocol
[
interface interface
[
interface-num
|
port-channel
]]
This example shows how to restart Rapid PVST+ on an Ethernet interface:
switch#
clear spanning-tree detected-protocol interface ethernet 1/8
Verifying the Rapid PVST+ Configuration
Use the following commands to display Rapid PVST+ configuration information.
Cisco Nexus 6000 Series NX-OS Layer 2 Switching Configuration Guide, Release 7.x
66
Configuring Rapid PVST+
Restarting the Protocol