Connectivity Guide
• Modify the max-age (in seconds) in CONFIGURATION mode, from 6 to 40, default 20.
spanning-tree vlan vlan-id max-age seconds
View RPVST+ global parameters
OS10# show spanning-tree active
Spanning tree enabled protocol rapid-pvst with force-version rstp
VLAN 1
Executing IEEE compatible Spanning Tree Protocol
Root ID Priority 32769, Address 90b1.1cf4.a523
Root Bridge hello time 2, max age 20, forward delay 15
Bridge ID Priority 32769, Address 90b1.1cf4.a523
We are the root of VLAN 1
Configured hello time 2, max age 20, forward delay 15
Setting spanning-tree link type for rapid state transitions
As specied in IEEE 802.1w, OS10 assumes a port that runs in full duplex mode as a point-to-point link. A point-to-point link transitions to
forwarding state faster. By default, OS10 derives the link type of a port from the duplex mode. You can override the duplex mode using the
spanning-tree link-type command.
As half-duplex mode is considered as a shared link, the fast transition feature is not applicable for shared links. If you designate a port as a
shared link, you cannot use the fast transition feature, regardless of the duplex setting.
To fasten the spanning-tree state transitions, you can set the link type to point-to-point. To set the link type to point-to-point:
• Use the following command in INTERFACE mode.
spanning-tree link-type point-to-point
MAC ush optimization
OS10 oers a MAC address clearing technique that optimizes the number of MAC ush calls sent by the Spanning Tree Protocol (STP)
module. For more information about this feature, see MAC ush optimization.
RPVST allows (VLAN, port) based ush until the number of calls sent is equal to the MAC ush threshold value that is congured.
When the number of calls sent exceeds the congured threshold, RPVST ignores further (VLAN, port) based ush and starts the MAC
ush timer. When the timer starts, the system blocks further ush. When the timer expires for that specic instance, the system triggers
VLAN-based ushing.
By default, the MAC ush threshold value is set to 5. However, Dell EMC recommends that you congure this value based on the number
of ports that participate in the STP topology.
RPVST+ commands
clear spanning-tree counters
Clears the counters for STP.
Syntax
clear spanning-tree counters [interface {ethernet node/slot/port[:subport] |
port—channel number}}]
344 Layer 2