Exam 200-301 topic 1 question 254 discussion

A priority 0 means that it guarantees the switch is always the root bridge of a particular VLAN. You don't need other information.

I just verified with a C2960 and a C1111 - Priority 0 ”beats” root primary, so the right answer is C indeed.

C is correct

STP is a golf game. Lowest score wins. So C is the correct answer. gg good day Go Dodgers

Pri 0 beats primary

Ok I tested it the Pri 0 commands wins the race over the root primary command I was wrong but know I know

D is correct the Root Primary wins the race

Welp, this question does not have enough context. Root primary DOES INDEED supersede priority 0, HOWEVER, if the switch with priority 0 has a lower mac address, it will supersede Root Primary... Poorly written question.

Correct answer is D, because of the manually configured Root Primary of Branch-4. As long it is well and alive Priority 0 doesn't matter. Guess in Cases like this Root Backup would be manually selected to, to prevent unexpected Root election results...

Ref: CCNP and CCIE Enterprise Core ENCOR 350-401 Official Cert Guide “Advanced STP Tuning … Root Bridge Placement Ideally the root bridge is placed on a core switch, and a secondary root bridge is designated to minimize changes to the overall spanning tree. Root bridge placement is accomplished by lowering the system priority on the root bridge to the lowest value possible, raising the secondary root bridge to a value slightly higher than that of the root bridge, and (ideally) increasing the system priority on all other switches. This ensures consistent placement of the root bridge. …” A. Branch-1 Wrong answer. B. Branch-2 Wrong answer. C. Branch-3 Correct answer. D. Branch-4 Wrong answer.

C is correct!

In this case the best answer is D To ensure the desired switch becomes the permanent root bridge for a specific vlan (in this scenario Vlan5) you must explicitly configure it as the primary https://www.omnisecu.com/cisco-certified-network-associate-ccna/how-to-configure-spanning-tree-protocol-root-primary-and-root-secondary.php think about it if you configure the switch with bridge priority 0 and connect another switch with bridge priority 0 and a lower mac address the root bridge will give up its position and change the topology wheres a switch with the primary role wont give up its position even if a switch with priority 0 and lower mac address is connected

I believe there is enough information. Branch 1 has lower priority then Branch 2 so it would become primary between those 2. If election was between Branch 1 and Branch 4 Branch 4 would lower value by 4096 and become primary...then Branch 3 would take primary as it has priority 0. If election was between branch 3 and Branch 1 first Branch 3 would take primary with priority 0. Since Branch 3 is already primary with a priority 0 it will not relinquish primary to Branch 4. Branch 4 will set its priority to 0 but Branch 3 will remain primary while it is active in the STP process.

Priority 0

Not enough information to answer. Both root primary and priority 0 will have a priority of 0, and go down to the lowest MAC address. Root primary will also generate SNMP complaints that it can't set it's priority to negative 4096, as primary always sets to 4096 below the lowest priority. Best answer is root primary.

Yeah C