13.
Rapid Spanning Tree Protocol (RSTP)
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contradictory information to be received from any Bridge following the change in
Spanning Tree information that first caused this Port to be assigned the Root Port or
Designated Port role.
OR
2. The Port is now a Root Port AND:
any Ports on the Bridge that have been Root Port too recently for Spanning Tree
information to have definitely reached all Bridges in the network
OR
any Ports have been contradicted if necessary, are not and will not be put in the
Forwarding Port State until that time has elapsed (with the exception of
3. below).
OR
3. The Port is:
a Designated Port and attaches to a LAN that has at most one other Bridge attached
AND
the other Bridge’s Port Role assignments are consistent with this port’s Bridge
AND
both Port States are known not to be Forwarding if they attach to LANs that connect to
Bridges whose Port Roles are not consistent with that Bridge.
OR
4. The Port is a Designated Port, attached to a LAN that is known not to be attached to any
other Bridge Ports.
Condition
1 above makes use of Forwarding Delay as the basis for establishing that enough
time has elapsed to allow the transition to the Forwarding state.
Configuring and Debugging RSTP
You can use RSTP configuration commands per switch or per interface.
To enable per-switch RSTP configuration commands, you must enter Protocol Configuration
mode, by using the following command in global Configuration mode:
device-name
(config)#
protocol
device-name
(cfg protocol)#
The (cfg protocol)# prompt-line indicates Protocol Configuration mode.
To access the RSTP interface configuration commands, use the following command in global
Configuration mode:
device-name
(config)#
interface
UU/SS/PP
device-name
(config-if UU/SS/PP)#