Topic: 200-301 topic 1 question 848
Which port state processes BPDUs, but does not forward packets or update the address database in Rapid PVST+?
A.
blocking
B.
learning
C.
listening
D.
disabled
Re: 200-301 topic 1 question 848
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
Re: 200-301 topic 1 question 848
out of available options ... Learning seems to be the most correct.
Blocking state is not available with RPVST+.
Re: 200-301 topic 1 question 848
I agree. Regarding the learning and blocking states, both process BPDUs, but do not update the MAC address table and do not forward packets. The key issue is that rapid-pvst does not use the blocking state (old STP), but DISCARDIND STATE, as it does not have this option, it only remains the letter B. "learning".
Re: 200-301 topic 1 question 848
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
Re: 200-301 topic 1 question 848
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
Re: 200-301 topic 1 question 848
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
Re: 200-301 topic 1 question 848
It´s A
Re: 200-301 topic 1 question 848
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
Re: 200-301 topic 1 question 848
Whoops; I mistyped my comment on B. I meant to say that the *learning* port does learn MAC addresses. I apologize for any confusion in my response. I'll provide the line straight from Cisco, to further clarify:
"A Layer 2 LAN port in the learning state prepares to participate in frame forwarding by learning the MAC addresses for the frames. The Layer 2 LAN port enters the learning state from the blocking state. "
See the first link in my original reply. It absolutely cannot be B.
Re: 200-301 topic 1 question 848
So many wrong answers.
Re: 200-301 topic 1 question 848
B is correct
Re: 200-301 topic 1 question 848
Answer is B the Blocking port status is not available in Rapid PVST
Re: 200-301 topic 1 question 848
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
Re: 200-301 topic 1 question 848
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
Re: 200-301 topic 1 question 848
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.
Re: 200-301 topic 1 question 848
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_1241757:~:text=Port%20States-,Rapid%20PVST%2B%20Port%20State%20Overview,-Propagation%20delays%20can
Re: 200-301 topic 1 question 848
B. Blocking
Re: 200-301 topic 1 question 848
i meant A. Blocking
Re: 200-301 topic 1 question 848
B - Learning
Re: 200-301 topic 1 question 848
The answer is A. Do not be misled. Read the official Cisco documentation: 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
Re: 200-301 topic 1 question 848
No i can't be A since Blocking is not a RSTP state. The three RSTP states are : Discarding, Learning and Forwarding