Exam 200-301 topic 1 question 848 discussion

The answer is 100% A. First of all, please do not confuse.. RSTP is NOT the same as Rapid PVST+. Rapid PVST+ has 4 different states, Blocking, Learning, Forwarding, Disabled. But RSTP has 3 different states, Discarding, Learning, Forwarding. For Rapid PVST+, the exact answer described by the question is "Blocking" state. For RSTP, it is "Learning" state. Again, the question is regarding Rapid PVST+. So the answer is A. Reference: https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5000/sw/layer2/503_n1_1/Cisco_n5k_layer2_config_gd_rel_503_N1_1_chapter9.html#con_1205207

out of available options ... Learning seems to be the most correct. Blocking state is not available with RPVST+.

Rapid PVST+ is Cisco’s implementation of RSTP (IEEE 802.1w) — with a key difference. If “Discarding” is not an option, and you're picking the closest equivalent: Then C. Listening is the best match — because it describes the behavior of processing BPDUs without forwarding or learning, just like Discarding does in RSTP.

blocking and listening are not valid state for Rapid PVST+. rather they are combined and call discarding state.

Chat GPT answer: In Rapid PVST+ (Per-VLAN Spanning Tree Plus), the port state that processes Bridge Protocol Data Units (BPDUs) but does not forward data packets or update the MAC address table is: C. listening In the listening state, the port will receive BPDUs and process them to ensure that loops do not occur. However, it will not forward any packets or update the address database during this state. The port will eventually transition to either the learning state or to forwarding state based on the topology changes and the spanning tree algorithm's decisions. Thus, the correct answer is C. listening.

Blocking: -> Receives BPDUs and directs them to the system module. -> Receives, processes, and transmits BPDUs received from the system module.

Rapid PVST+ (IEEE 802.1w) is an enhanced version of PVST+ and allows for faster spanning-tree calculations and convergence in response to Layer 2 topology changes. Rapid PVST+ defines three port states: discarding, learning, and forwarding, and provides multiple

A ist correct RPVST+ has 4 Port States: Blocking State Learning State Forwarding State Disabled State Blocking State: - Does not incorporate the end station location into its address database. (There is no learning on a blocking Layer 2 LAN port, so there is no address database update.) - Receives BPDUs and directs them to the system module. - Receives, processes, and transmits BPDUs received from the system module. Learning State: - Incorporates the end station location into its address database. - Receives BPDUs and directs them to the system module. - Receives, processes, and transmits BPDUs received from the system module. So BLOCKING STATE dosen‘t update the address database but LEARNING STATE does. https://www.cisco.com/c/en/us/td/docs/switches/datacenter/sw/4_2/nx-os/layer2/configuration/guide/Cisco_Nexus_7000_Series_NX-OS_Layer_2_Switching_Configuration_Guide_Release_4-2_chapter6.html#con_1067031

Blocking State A LAN port in the blocking state does not participate in frame forwarding. A LAN port in the blocking state performs as follows: Discards frames received from the attached segment. Discards frames switched from another port for forwarding. Does not incorporate the end station location into its address database. (There is no learning on a blocking LAN port, so there is no address database update.) Receives BPDUs and directs them to the system module. Receives, processes, and transmits BPDUs received from the system module. Receives and responds to network management messages. https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5000/sw/layer2/503_n1_1/Cisco_n5k_layer2_config_gd_rel_503_N1_1_chapter9.html#con_1205207

It´s A

It's A; this is despite the "blocking" port state not existing in Rapid PVST+. Let's look at the other answers: B -> The question specifically mentions not updating the address database, i.e. learnning MAC addresses. The listening port *does* learn MAC addresses in RPVST+. This is why it can't be B. C -> Does not exist in RPVST+; its RPVST+ equivalent is the "discarding" state. D -> Disabled ports don't process BPDUs; incorrect. Also note that STP and RPVST+ ports will both show up as "BLK" when using the command "show spanning-tree". Also note that official Cisco documentation refers to the RPVST+ discarding state as "blocking". Since B is ruled out, A is the only viable option. https://www.cisco.com/c/en/us/td/docs/switches/datacenter/sw/4_2/nx-os/layer2/configuration/guide/Cisco_Nexus_7000_Series_NX-OS_Layer_2_Switching_Configuration_Guide_Release_4-2_chapter6.html#con_1489943 https://www.cisco.com/c/en/us/support/docs/lan-switching/spanning-tree-protocol/24062-146.html#toc-hId--1875401080

So many wrong answers.

B is correct

Answer is B the Blocking port status is not available in Rapid PVST

Port States paragraph at: https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus3000/sw/layer2/503_U1_1/Cisco_n3k_layer2_config_gd_503_U1_1_chapter7.html#d3275e861_navtitle

Learning = Interim state with MAC learning and without forwarding. Also blocking or disable are not RPVST+ port state. So the question is broken. But most accurate answer is B, idk

Configuring Rapid PVST+ https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus5000/sw/layer2/503_n1_1/Cisco_n5k_layer2_config_gd_rel_503_N1_1_chapter9.html#con_1241802 Blocking State A LAN port in the blocking state does not participate in frame forwarding. A LAN port in the blocking state performs as follows: Discards frames received from the attached segment. Discards frames switched from another port for forwarding. Does not incorporate the end station location into its address database. (There is no learning on a blocking LAN port, so there is no address database update.) Receives BPDUs and directs them to the system module. Receives, processes, and transmits BPDUs received from the system module. Receives and responds to network management messages.