Exam 200-105 topic 1 question 494 discussion

Switchport trunk is used on trunk links but here we have a pc connected to the switch via an access port. So we either enable port fast on the interface level or globally using the "default" keyword.

Answer is C. Please note that the keyword "Switch(config-if)" is used for entering port commands. So A and B is incorrect. D should remove the "no" keyword in the command.

Answer is B. Command "spanning-tree portfast default" enable portfast on all access port. Question asked for a pc to connect to this port, so it's clearly an access port.

Switch(config)# spanning-tree portfast default - this command works only on access ports. To exclusively allow all ports whether trunk or access we need to type 'trunk' instead of 'default'. Hence the answer should be C.

Answer is "B"

So vague and many possible answer.

Can be activated either on port using spanning-tree portfast or globally using spanning-tree portfast default

Although this question said “which command on a port” but it gave two answers in global configuration mode so it is a bit unclear. But we believe the correct answer should be “spanning-tree portfast default”, which enables PortFast on all non-trunking interfaces. Note: The command “spanning-tree portfast trunk” enables portfast on a trunk port. The trunk port enters the STP forwarding-state immediately or upon a linkup event, thus bypassing the listening and learning states.

Answer is "B". As it mentions PC we can assume that "PC" is in access mode on switch, so command "spanning-tree portfast default" automatically turns on portfast on access ports and not on trunk ports.

Since it specifically mentions a PC, The answer is B. "The spanning-tree portfast default global configuration mode command enables PortFast on all non-trunking interfaces."

I believe it is B as it does not explicitly says the config needs to be on an interface or globally.

The answer should be A. Explanation: https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3560/software/release/12-2_55_se/configuration/guide/3560_scg/swstpopt.html At the global level, you enable BPDU guard on Port Fast-enabled ports by using the spanning-tree portfast bpduguard default global configuration command. Spanning tree shuts down ports that are in a Port Fast-operational state if any BPDU is received on them. In a valid configuration, Port Fast-enabled ports do not receive BPDUs. Receiving a BPDU on a Port Fast-enabled port means an invalid configuration, such as the connection of an unauthorized device, and the BPDU guard feature puts the port in the error-disabled state. When this happens, the switch shuts down the entire port on which the violation occurred.

I believe it is D but then wrote the answer wrong. Should remove the "no". B would be correct if the question was worded to be "Globally" but it says a PORT and a PC. Thats my two cents for this.

Answer: B

The correct answer is C. - You can enable this feature by using the spanning-tree portfast interface configuration or the spanning-tree portfast default global configuration command.