多选题Which three statements about RSTP are true?（）ARSTP significantly reduces topology reconverging time after a link failure.BRSTP expends the STP port roles by adding the alternate and backup roles.CRSTP port atates are blocking,discarding,learing,or forw

RSTP cannot operate with PVST+.

RSTP defines new port roles.

RSTP defines no new port states.

RSTP is a proprietary implementation of IEEE 802.1D STP.

RSTP is compatible with the original IEEE 802.1D STP.

The designated port is the switch port on every nonroot bridge that is the chosen path to theroot bridge. There can be only one designated port on every switch. The designated portassumes the forwarding state in a stable active topology. All switches connected to a given segment listen to all BPDUs and determine the switch that will be the root switch for a particular segment.

The disabled port is an additional switch port on the designated switch with a redundant link to the segment for which the switch is designated. A disabled port has a higher port ID than the disabled port on the designated switch. The disabled port assumes the discarding state in astable active topology.

The backup port is a switch port that offers an alternate path toward the root bridge. The backup port assumes a discarding state in a stable， active topology. The backup port will be present on nondesignated switches and will make a transition to a designated port if the current designated path fails.

The root port is the switch port on every nonroot bridge that is the chosen path to the root bridge. There can be only one root port on every switch. The root port assumes the forwarding state in a stable active topology.

Upon bootup，a port transitions from blocking to forwarding because it assumes itself as root.

Upon bootup，a port transitions from blocking to listening because it assumes itself as root.

Upon bootup，a port transitions from listening to forwarding because it assumes itself as root.

If a forwarding port receives no BPDUs by the max_age time limit， it will transition to listening.

If a forwarding port receives an inferior BPDU， it will transition to listening.

If a blocked port receives no BPDUs by the max_age time limit， it will transition to listening.

STP will be disabled on the port.

PortFast can also be configured on trunk ports.

PortFast is required to enable port-based BPDU guard.

PortFast is used for both STP and RSTP host ports.

PortFast is used for STP-only host ports.

BPDU port-guard can be enabled globally， whereas BPDU filtering must be enabled on a per-interface basis.

When globally enabled， BPDU port-guard and BPDU filtering apply only to PortFast enabled ports.

When globally enabled， BPDU port-guard and BPDU filtering apply only to trunking-enabled ports.

When a BPDU is received on a BPDU port-guard enabled port， the interface goes into the err-disabled state.

When a BPDU is received on a BPDU filtering enabled port， the interface goes into the err-disabled state.

When a BPDU is received on a BPDU filtering enabled port， the interface goes into the STP blocking state.

root

designated

alternate

backup

forwarding

learning

RSTP significantly reduces topology reconverging time after a link failure.

RSTP expends the STP port roles by adding the alternate and backup roles.

RSTP portatates are blocking,discarding,learing,orforwarding.

RSTP also uses the STP proprsal-agreement sequence.

RSTP use the same timer-baseed process as STP on point-to-point links.

RSTP provides a faster transition to the forwarding state on point-to-point links than STP does.

RSTP significantly reduces topology reconverging time after a link failure.

RSTP expends the STP port roles by adding the alternate and backup roles.

RSTP port states are blocking，discarding，learing，or forwarding.

RSTP also uses the STP proprsal-agreement sequence.

RSTP use the same timer-baseed process as STP on point-to-point links.

RSTP provides a faster transition to the forwarding state on point-to-point links than STP does.

 an edge port that transitions to the forwarding state

 a non-edge port that transitions to the blocking state

 a non-edge port that transitions to the forwarding state

 an edge port that transitions to the blocking state

 any port that transitions to the blocking state

 any port that transitions to the forwarding state

BPDUs that enter a blocking port are discarded.

BPDUs that enter a blocking port are processed.

Loopguard puts an interface into a loop-inconsistent state when BPDUs stop being received on a blocking port.

BPDUs are only processed on forwarding ports.

Listening

Learning

Forwarding

Blocking

Discarding

Disabled

RSTP significantly reduces topology reconverging time after a link failure.

RSTP expends the STP port roles by adding the alternate and backup roles.

RSTP port atates are blocking，discarding，learing，orforwarding.

RSTP also uses the STP proprsal-agreement sequence.

RSTP use the same timer-baseed processas STP on point-to-pointlinks.

RSTP provides a faster transition to the forwarding state on point-to-point links than STP does.

a root port being transitioned to the blocking state

a port being assigned as a root port

a port being assigned as an alternate port

a root port being transitioned to the forwarding state