100% Latest & Updated Cisco 200-301 Practice Test Questions, Exam Dumps & Verified Answers!
30 Days Free Updates, Instant Download!
Question 260
A port changes from discarding to forwarding in RSTP; the operator must verify the rapid role/state transition without treating all discarded ports as physical failures. Which RSTP state information should be inspected?
- Inspect only the Ethernet administrative shutdown flag
- Inspect only IP route metrics
- Inspect rapid spanning-tree role and state transitions
- Inspect only CAM table aging time
Explanation
Correct Answer
C:Rapid PVST+ can promote an alternate path during topology changes.
Incorrect Answers
A:Administrative status cannot distinguish RSTP discarding, learning and forwarding on an otherwise up Ethernet interface.
B:Layer 3 path costs do not identify a specific RSTP port role and port state transition.
D:Aging timer values do not show the negotiated RSTP role/state transitions of the port.
Question 261
A Catalyst IOS switch already has PortFast enabled on its approved user-facing access ports. Security policy requires every such operational edge port to inherit BPDU Guard by default, rather than configuring each port separately. Which global configuration command applies that policy?
- spanning-tree portfast bpdufilter default
- spanning-tree loopguard default
- spanning-tree portfast bpduguard default
- spanning-tree guard root on a single interface
Explanation
Correct Answer
C:The global portfast bpduguard default command applies BPDU Guard to operational PortFast ports; an unexpected BPDU can then errdisable such an edge port without individual guard lines.
Incorrect Answers
A:Global BPDU filtering suppresses BPDU processing and may conceal loops; it does not errdisable PortFast edge ports when BPDUs arrive.
B:Loop Guard protects eligible non-designated links when expected BPDUs disappear, not user edge ports from newly received BPDUs.
D:Root Guard applies to specific designated downstream links to prevent superior-root takeover; the shown interface-level action is not the requested global PortFast BPDU Guard policy.
Question 262
A distribution switch must remain the spanning-tree root for VLAN 30. Its designated downstream switch-to-switch port begins hearing superior BPDUs from a misconfigured access switch. The desired protection blocks root takeover without treating every normal BPDU as a host-edge violation. Which guard fits?
- BPDU Guard with PortFast on the interswitch trunk
- Loop Guard on the designated downstream port
- BPDU Filter to suppress all spanning-tree messages
- Use Root Guard
Explanation
Correct Answer
D:Root Guard on a designated downstream port blocks a switch claiming superior root status into root-inconsistent state and automatically recovers after the superior advertisement stops.
Incorrect Answers
A:BPDU Guard is intended for verified edge links and typically errdisables upon receipt of any BPDU; ordinary interswitch links exchange BPDUs.
B:Loop Guard protects non-designated ports when BPDUs stop arriving, not a designated link that receives superior root-election information.
C:Suppressing STP BPDUs can hide a loop and is not the selective root-inconsistent protection required by this scenario.
Question 263
A switch with Loop Guard has put a formerly alternate uplink into the loop-inconsistent state after expected BPDUs disappeared. The fiber neighbor later resumes valid BPDU transmission on that link. What recovery behavior should the operator expect if the port is otherwise healthy?
- The operator must disable spanning tree globally because Loop Guard cannot recover without a switch reload
- The interface will become the elected STP root bridge regardless of advertised bridge priority
- BPDU Guard will automatically errdisable the interswitch uplink when ordinary BPDUs return
- Loop Guard can clear loop-inconsistent when valid BPDUs return, allowing normal STP role/state evaluation
Explanation
Correct Answer
D:Once normal BPDUs resume on the protected port, Loop Guard can remove the loop-inconsistent block so ordinary spanning-tree calculations determine whether it forwards or remains alternate.
Incorrect Answers
A:Loop Guard protects a specific link from a missing-BPDU forwarding error; a global STP shutdown is not its required recovery behavior.
B:Receiving BPDUs again does not override spanning-tree bridge-ID and path-cost comparisons or make this switch the root by itself.
C:BPDU Guard is an edge-port policy that reacts to received BPDUs; Loop Guard on a legitimate uplink instead expects and uses them.
Question 264
A lab-only edge switchport has been explicitly approved to suppress all inbound and outbound spanning-tree BPDUs, accepting the resulting loop risk. On a supported Catalyst IOS XE port, which **interface-level feature** performs this filtering rather than shutting the port down when a BPDU arrives?
- Enable `spanning-tree bpduguard enable`
- Enable `spanning-tree guard root`
- Enable `spanning-tree guard loop`
- Enable `spanning-tree bpdufilter enable`
Explanation
Correct Answer
D:Interface BPDU Filter suppresses BPDU send/receive. Cisco warns this is similar to disabling STP on the port and can create Layer 2 loops, so it is not a general edge-safety recommendation.
Incorrect Answers
A:BPDU Guard reacts to received BPDUs by errdisabling an edge port rather than silently filtering BPDUs in both directions.
B:Root Guard prevents a designated port from becoming a root port when it receives superior BPDUs, not all BPDU transmission/reception.
C:Loop Guard protects non-designated ports from losing expected BPDUs; it does not unconditionally filter BPDUs.
Question 265
A supported Catalyst IOS XE switch has many verified workstation-facing access ports. The administrator wants those nontrunking edge ports to receive the PortFast edge behavior by default, rather than editing each one independently. Which global command is appropriate on the documented platform?
- spanning-tree portfast edge bpdufilter default, disabling BPDU sending in the edge policy
- spanning-tree loopguard default, protecting non-designated uplinks on BPDU loss
- spanning-tree portfast edge bpduguard default, guarding only already-PortFast edges against received BPDUs
- spanning-tree portfast edge default, setting the global access-port edge behavior
Explanation
Correct Answer
D:The global portfast edge default command enables the PortFast edge treatment for normal access ports on the supported IOS XE command family; avoid applying it indiscriminately to genuine interswitch links.
Incorrect Answers
A:BPDU filtering is a different and potentially hazardous control that changes BPDU behavior, not the baseline policy for rapid edge-port forwarding.
B:Loop Guard is for ports that should continue hearing BPDUs on legitimate redundant links, not a default host-edge transition mechanism.
C:The global BPDU Guard default controls the reaction to received BPDUs on PortFast edges; it is not the command that first sets the normal access ports to an edge port type.
Question 266
A Rapid PVST+ status display lists Gi1/0/8 as role 'Altn' and state 'DSC' while the chosen root port is forwarding. Which interpretation correctly separates the port's role from its operational state?
- The role is designated and the state is forwarding, so the link carries normal user traffic
- The role is root and the state is learning, so the link is selected for transit but cannot yet forward
- The role is disabled and the state is administratively shut, so no BPDUs are processed
- The role is alternate and the state is discarding, providing standby root reachability without user forwarding
Explanation
Correct Answer
D:Altn is the backup root-path role; DSC is the RSTP state that prevents ordinary MAC learning and user-frame forwarding on that backup.
Incorrect Answers
A:A designated forwarding port differs from an alternate discarding port; the shown status does not advertise an active segment forwarding role.
B:A root port is the preferred path to the root, and learning is a transient state; neither field equals the displayed alternate/discarding pair.
C:Alternate STP ports can remain operational and process BPDUs while blocking user frames; they are not necessarily administratively disabled.
Question 267
An RSTP-controlled switchport is not learning dynamic MAC addresses and is not forwarding user frames while topology protection holds it out of service. Which RSTP port state matches both behaviors?
- Discarding
- Learning
- Forwarding
- Listening as a distinct RSTP 802.1w state
Explanation
Correct Answer
A:The discarding state neither learns source MAC entries nor forwards ordinary user traffic; it may occur for several port roles.
Incorrect Answers
B:Learning permits MAC learning while withholding user-frame forwarding, so it does not match the stated lack of learning.
C:Forwarding passes user frames and learns MAC addresses, contrary to both observations.
D:RSTP uses discarding, learning, and forwarding states; listening is a legacy 802.1D state, not a separate standard RSTP state.
Question 268
A selected RSTP designated port on the active topology has completed transition and forwards ordinary data frames. Which port state indicates active data forwarding?
- RSTP discarding state
- RSTP learning state
- RSTP alternate-port role on a redundant blocked path
- RSTP forwarding state
Explanation
Correct Answer
D:Forwarding is the stable state permitting normal user frame delivery.
Incorrect Answers
A:A discarding port does not forward ordinary end-user Ethernet data, regardless of physical link state.
B:A learning port builds its MAC table but has not yet transitioned into normal data forwarding.
C:The alternate role usually supplies a standby path in discarding, not the designated port stated to be actively forwarding.
Question 269
A switch has one root port and a second nonforwarding backup uplink to the same root bridge. What RSTP port role names that alternate route?
- A designated-port role for the backup uplink
- An alternate role port
- A second root-port role on the same switch
- An edge PortFast role assigned to the interswitch uplink
Explanation
Correct Answer
B:An alternate role is a backup root path that is normally discarding.
Incorrect Answers
A:A designated port forwards for its segment; the stated redundant uplink provides a nonforwarding alternative to the root path.
C:A non-root bridge ordinarily chooses one root port; another viable root path is classified as alternate.
D:PortFast is used on appropriate edge ports and is not the designated alternate path classification for redundant switch-to-switch connections.
Question 270
On a shared Ethernet segment, the switch advertising the best path toward the root supplies the one forwarding port for that segment. Which RSTP port role is elected there?
- An alternate port blocked from forwarding
- The root port on every switch across the segment
- A designated role port
- A backup port on shared media where another same-switch port is designated
Explanation
Correct Answer
C:A root bridge has designated ports on its connected segments in the active topology.
Incorrect Answers
A:The alternate route is a standby route toward the root, not the best-path forwarding port elected for this segment.
B:A root port is each non-root switch’s chosen port toward the root bridge; the best port selected for the shared segment is designated.
D:A backup role is a distinct nonforwarding redundant port scenario; it is not the one designated forwarding segment port.
Cisco Certified Network Associate (CCNA) (200-301) Practice Tests
