Exam 200-301 topic 1 question 300 discussion

Strange question... In Rapid-PVST+, there's no listening state anymore

The answer is D, folks. To quote the Official Certification Guide Volume 1 Page 612: Max Age -> "How long any switch should wait, after ceasing to hear Hellos, before trying to change the STP topology. Forward Delay -> "Delay that affects the process that occurs when an interface changes from blocking state to forwarding state. A port stays in an interim listening state, and then an interim learning state, for the number of seconds defined by the forward delay timer." Now, looking at official Cisco docs, we can see the command to change the forward delay time is indeed "forward-time". https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst4500/12-2/15-02SG/configuration/guide/config/spantree.html#56177

The max-age parameter controls the maximum age of STP messages in the network, which is the maximum amount of time that a switch will retain information about the network topology before discarding it. By default, the max-age is set to 20 seconds. However, in Rapid PVST+, the max-age can be set as low as 6 seconds to allow for faster convergence.

D is correct

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#task_1197376

Answer D explanation, it is a backup configuration but it still valid... "Determines how long each of the listening and learning states last before the port begins forwarding. This timer is generally not used by the protocol but is used as a backup. The default is 15 seconds, and the range is from 4 to 30 seconds."

D seems correct

The maximum age timer controls the maximum time that a switch port will wait for a BPDU (Bridge Protocol Data Unit) from the root bridge before declaring the current root bridge as lost and initiating a new election process. Option A (Wrong) configures the priority of the switch for a specific VLAN. Option B (Wrong) configures the hello time for STP messages in the network. Option D (Wrong) configures the forwarding delay time for STP.

Gather here and explain to me why D and not C

Confirm write answer D. Search "Rapid PVST+ Protocol Timers" in following link: 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 Regards,

C. switch(config)#spanning-tree vlan 1 max-age 6 Explanation: The max-age parameter controls the maximum age of STP messages in the network, which is the maximum amount of time that a switch will retain information about the network topology before discarding it. By default, the max-age is set to 20 seconds. However, in Rapid PVST+, the max-age can be set as low as 6 seconds to allow for faster convergence. Option A sets the priority of the switch for a specific VLAN. This does not affect the listen and learn time period. Option B sets the hello time for STP messages in the network. This does not affect the listen and learn time period. Option D sets the forwarding delay time for STP. This does not affect the listen and learn time period.

Forward time : Determines how long each of the listening and learning states last before the port begins forwarding. Switch(config)# [ no ] spanning-tree vlan vlan_ID forward-time forward_time Configures the forward time of a VLAN. The forward_time value can be from 4 to 30 seconds. https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst4500/12-2/15-02SG/configuration/guide/config/spantree.html#56177