Reference Guide

Interface
Name Role PortID Prio Cost Sts Cost Link-type Edge
-------------------------------------------------------------------------
ethernet1/1/1 Disb 128.260 128 200000000 BLK 0 AUTO No
ethernet1/1/2 Disb 128.264 128 200000000 BLK 0 AUTO No
ethernet1/1/3 Disb 128.268 128 200000000 BLK 0 AUTO No
ethernet1/1/4 Disb 128.272 128 200000000 BLK 0 AUTO No
ethernet1/1/5:1 Disb 128.276 128 200000000 BLK 0 AUTO No
Global parameters
The root bridge sets the values for forward-time, hello-time, and max-age, and overwrites the values set on other bridges
participating in the RSTP group. Dell EMC recommends that only experienced network administrators change the RSTP group
parameters. Poorly planned modification of the RSTP parameters can negatively affect network performance.
Forward-time 15 seconds — Amount of time an interface waits in the Listening state and the Learning state before it
transitions to the Forwarding state.
Hello-time 2 seconds — Time interval in which the bridge sends RSTP BPDUs.
Max-age 20 seconds — Length of time the bridge maintains configuration information before it refreshes that
information by recomputing the RSTP topology.
Port cost Port cost values to set the path cost of the interface:
● 100-Mb/s Ethernet interfaces — 200000
● 1-Gigabit Ethernet interfaces — 20000
● 10-Gigabit Ethernet interfaces — 2000
● 40-Gigabit Ethernet interfaces — 500
● Port-channel with 100 Mb/s Ethernet interfaces — 200000
● Port-channel with 1-Gigabit Ethernet interfaces — 20000
● Port-channel with 10-Gigabit Ethernet interfaces — 2000
● Port-channel with 1x40Gigabit Ethernet interface — 500
● Port-channel with 2x40Gigabit Ethernet interfaces — 250
● Change the forward-time in CONFIGURATION mode (4 to 30, default 15).
spanning-tree rstp forward-time seconds
● Change the hello-time in CONFIGURATION mode (1 to 10, default 2). With large configurations (especially those
configurations with more ports) Dell EMC recommends increasing the hello-time.
spanning-tree rstp hello-time seconds
● Change the max-age in CONFIGURATION mode (6 to 40, default 20).
spanning-tree rstp max-age seconds
View current interface parameters
OS10# show spanning-tree active
Spanning tree enabled protocol rstp with force-version rstp
Executing IEEE compatible Spanning Tree Protocol
Root ID Priority 32768, Address 90b1.1cf4.9b8a
Root Bridge hello time 2, max age 20, forward delay 15
Bridge ID Priority 32768, Address 90b1.1cf4.9b8a
We are the root
Configured hello time 2, max age 20, forward delay 15
Interface Designated
Name PortID Prio Cost Sts Cost Bridge ID PortID
-------------------------------------------------------------------
ethernet3/1/1 244.128 128 500 BLK 0 32768 90b1.1cf4.9b8a 128.244
ethernet3/1/2 248.128 128 500 BLK 0 32768 90b1.1cf4.9b8a 128.248
ethernet3/1/3 252.128 128 500 FWD 0 32768 90b1.1cf4.9b8a 128.252
ethernet3/1/4 256.128 128 500 BLK 0 32768 90b1.1cf4.9b8a 128.256
Interface
Name Role PortID Prio Cost Sts Cost Link-type Edge
226
Layer 2