Users Guide
ethernet1/1/2 248.128 128  500  BLK 0    32768 90b1.1cf4.9b8a  128.248
ethernet1/1/3 252.128 128  500  FWD 0    32768 90b1.1cf4.9b8a  128.252
ethernet1/1/4 256.128 128  500  BLK 0    32768 90b1.1cf4.9b8a  128.256
Interface
Name          Role PortID  Prio Cost Sts Cost Link-type Edge
---------------------------------------------------------- 
ethernet1/1/1 Altr 128.244 128  500  BLK 0    AUTO      No
ethernet1/1/2 Altr 128.248 128  500  BLK 0    AUTO      No
ethernet1/1/3 Root 128.252 128  500  FWD 0    AUTO      No
ethernet1/1/4 Altr 128.256 128  500  BLK 0    AUTO      No
Interface parameters
Set the port cost and port priority values on interfaces in L2 mode.
Port cost Value based on the interface type. The previous table lists the default values. The greater the port cost,
the less likely the port is selected as a forwarding port.
Port priority Influences the likelihood a port is selected to be a forwarding port in case several ports have the same
port cost.
● Change the port cost of an interface in INTERFACE mode, from 1 to 200000000.
spanning-tree rstp cost cost
● Change the port priority of an interface in INTERFACE mode, from 0 to 240, default 128.
spanning-tree rstp priority priority-value
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
------------------------------------------------------------------- 
ethernet1/1/1 244.128 128  500  BLK 0    32768 90b1.1cf4.9b8a  128.244
ethernet1/1/2 248.128 128  500  BLK 0    32768 90b1.1cf4.9b8a  128.248
ethernet1/1/3 252.128 128  500  FWD 0    32768 90b1.1cf4.9b8a  128.252
ethernet1/1/4 256.128 128  500  BLK 0    32768 90b1.1cf4.9b8a  128.256
Interface
Name          Role PortID  Prio Cost Sts Cost Link-type Edge
---------------------------------------------------------- 
ethernet1/1/1 Altr 128.244 128  500  BLK 0    AUTO      No
ethernet1/1/2 Altr 128.248 128  500  BLK 0    AUTO      No
ethernet1/1/3 Root 128.252 128  500  FWD 0    AUTO      No
ethernet1/1/4 Altr 128.256 128  500  BLK 0    AUTO      No
Root bridge selection
RSTP determines the root bridge. Assign one bridge a lower priority to increase the likelihood that it is selected as the root
bridge.
● Assign a number as the bridge priority or designate it as the primary or secondary root bridge in CONFIGURATION mode.
Configure the priority value range, from 0 to 65535 in multiples of 4096, default 32768. The lower the number assigned, the
more likely the bridge becomes the root bridge.
spanning-tree rstp priority priority-value
Layer 2
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