Exam 350-401 topic 1 question 185 discussion

The correct answers would look to be A & E. Priority is chosen based on the upstream port, therefore we need to make this change on DSW2. This means answers B and D are out. Port priority is set in increments of 16: Switch(config-if)#spanning-tree port-priority ? <0-240> port priority in increments of 16 This leaves us with C or E. C is the default, so won't change the behaviour here, so it's out too. The only two still standing are A & E.

Correct Answer here is B, D DSW2 will be elected as root bridge. So all the ports of a root bridge are in forwarding mode. DSW1 has to make the decision to block redundant ports. Default port priority is 128, so interface number breaks the tie. In this case Gi1/3 on DSW1 will be blocked. To prefer Gi1/3 over Gi1/2 the port priority has to be lower than 128. the most appropriate answer is DSW1(config-if)#spanning-tree port-priority 0. Before applying this command you need to apply DSW1(config)#interface gi1/3 The priority values are 0, 32, 64, 96, 128, 160, 192, and 224. All other values are rejected. https://www.cisco.com/c/m/en_us/techdoc/dc/reference/cli/n5k/commands/spanning-tree-port-priority.html#:~:text=The%20priority%20values%20are%200,is%20the%20default%20STP%20mode.

IMO B&D should be the correct answer unless if DSW1 is the RB for vlan 10, then A&E become correct

Answer is B&D . Since DSW2 is root bridge and all its ports disgnated. We need to change the configuration on DSw1

ANS B&D.. DSW2 is the root bridge , it has the lowest priority , the port priority needs to be changed on SW1 , as all ports on DSW2 are FWD , DSW1 Gi1/3 is BLK so it needs to have a lower port priority than DSW1 gi1/2 setting Gi1/3 to 0 will make it the RP as it should be lower than the default port priority on Gi1/2 ( assume Gi1/2 is configured with the default value )

A & E are correct

If you think BD is right, please read Asymptote explantion. For sure AE is the only option. If you still think BD you misunderstand the fare end port priority.

A&E are the correct answers

the answer is A/E. the reference: https://www.ciscopress.com/articles/article.asp?p=2995351&seqNum=2

In the DSW1,DSW2,ASW1,ASW2 STP domain the DSW2 has the best prio:24576 port priority has to be modified on the upstream switch (DSW2).

The correct answer is A&E

I am having a tough time with this one. The answer can be B or E. (but definitely A) DSW2(config-if)#spanning-tree port-priority ? <0-240> port priority in increments of 16 you can actually set it to 0 or 16 and DSW1 will see it as a root port. Interface Role Sts Cost Prio.Nbr Type ------------------- ---- --- --------- -------- -------------------------------- Gi1/2 Altn BLK 4 128.1 P2p Gi1/3 Root FWD 4 128.2 P2p So im not too sure what the right answer is.

You should open the interface you want to configure. "A" opens the correct interface and "E" configures it. AE are the correct answers

Is the only answer I can see that makes sense

One thing we can all agree on, can't be DE as given answer says. D is starting configuration on SW1, E continues the interface configuration on SW2. Mismatched pairs. Only choice pairs that can be chosen are AE or BD. Choice C is default port priority so that's out if you think you should configure SW2, not relevant if you think you should configfure SW1. I misread the text saying all PORT priorities are at defaults, thinking it said all switch priorities are defaults, though the exhibit shows the two distribution switches have different priorities. Either way, switch priorities same or as exhibited, bridge MAC makes SW2 root. That makes all its ports designated, so it is SW1 that needs to decide whether either of the ports between then are RP or blocked. Only way to do this is by setting port priority. But SW1 will be going by the port priority it sees reported by SW2, NOT by what SW1 ports are set to. So must make configuration change at SW2. Answer therefore must be AE

You're all mistaken. To change the port priority on a switch you have to change the adjacent port on the upstream switch. It's B&D. It's page 64 of the OCG.

A and E