Administrator Guide
Enabling SNMP Traps for Root Elections and Topology
Changes
To enable SNMP traps, use the following command.
• Enable SNMP traps for RSTP, MSTP, and PVST+ collectively.
snmp-server enable traps xstp
Modifying Interface Parameters
On interfaces in Layer 2 mode, you can set the port cost and port priority values.
• Port cost — a value that is based on the interface type. The previous table lists the default values. The greater the port cost, the less
likely the port is selected to be a forwarding port.
• Port priority — inuences the likelihood that a port is selected to be a forwarding port in case that several ports have the same port
cost.
To change the port cost or priority of an interface, use the following commands.
• Change the port cost of an interface.
INTERFACE mode
spanning-tree rstp cost cost
The range is from 0 to 65535.
The default is listed in the previous table.
• Change the port priority of an interface.
INTERFACE mode
spanning-tree rstp priority priority-value
The range is from 0 to 15.
The default is 128.
To view the current values for interface parameters, use the show spanning-tree rstp command from EXEC privilege mode.
Enabling SNMP Traps for Root Elections and Topology
Changes
To enable SNMP traps collectively, use this command.
Enable SNMP traps for RSTP, MSTP, and PVST+ collectively.
snmp-server enable traps xstp
Inuencing RSTP Root Selection
RSTP determines the root bridge, but you can assign one bridge a lower priority to increase the likelihood that it is selected as the root
bridge.
To change the bridge priority, use the following command.
Rapid Spanning Tree Protocol (RSTP)
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