| Question 1 | Which STP enhancement takes a port out of the STP topology and always keeps it in a forwarding state? A. UplinkFast B. PortFast C. Rapid STP D. Edge port
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| A1: | Answer B is correct. PortFast is a Cisco-proprietary STP feature that places a port in a forwarding state and removes it from the STP topology changes on this port do not affect the STP topology. UplinkFast is used to detect a failed root port connection and immediately use a backup link that is currently in blocking mode. Therefore, answer A is incorrect. RSTP is an enhancement to the STP (802.1D) algorithm, which makes answer C incorrect. Answer D is similar to PortFast, but is a part of RSTP. An edge port is connected to a nonswitch device and kept in a forwarding state. If a switch is detected off of the port, the port is included in the RSTP topology and the algorithm is rerun, making answer D incorrect. |
| Question 2 | In order for UplinkFast to function, the redundant port must be in a __________ state. A. Blocking B. Listening C. Learning D. Forwarding
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| A2: | Answer A is correct. The redundant port must be in a blocked state for UplinkFast to use it when the root port fails. If a port is in any other state, UplinkFast cannot use the backup port, making answers B, C, and D incorrect. |
| Question 3 | In RSTP, what type of port is similar to Cisco's PortFast enhancement? A. Backup B. Secondary C. Uplink D. Edge
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| A3: | Answer D is correct. An edge port is a port connected to a nonswitch device. It is kept in a forwarding state and is not part of the STP topology unless BPDUs are seen on the port. Answers A and B are nonexistent port types. An uplink port is a connection from a lower layer switch (like access) to a higher one (like distribution), making answer C incorrect. |
| Question 4 | Which RSTP port role allows a port to be a redundant designated port? A. Root B. Alternate C. Backup D. Secondary
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| A4: | Answer C is correct. A backup port is a redundant designated port that is placed in a blocking state. If the designated port fails, the backup port can be activated. Answer A is incorrect because the root port is the best port on the switch used to reach the root switch. Answer B is incorrect because the alternate port is a backup of the root port. Answer D is incorrect because it is a nonexistent port role. |
| Question 5 | Which STP allows multiple VLANs to share the same STP instance? A. MST B. CST C. PVST D. IST
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| A5: | Answer A is correct. IEEE's MST uses instances to group VLANs in order to share a common STP configuration. Answer B is incorrect because CST supports only a single instance of STP. Answer C is incorrect because PVST supports a separate instance for each VLAN, not shared instances. Answer D is incorrect because MST uses IST to make MST appear as a single virtual switch to other switches that only support CST. |
| Question 6 | Which of the following does not have to match in order for switches to belong to the same MST region? A. Region name B. Revision number C. VLAN table contents D. Priority
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| A6: | Answer D is correct. The priority affects a switch's ID or a port's priority when choosing port types. Answers A, B, and C must be the same in order for two switches to belong to the same region, making these answers incorrect. |
| Question 7 | You can have up to _________ connections in an EtherChannel. |
| A7: | Answer C is correct. You can have up to 8 connections (half- or full duplex) in an EtherChannel. Therefore, answers A, B, and D are incorrect. |
| Question 8 | Which EtherChannel protocol is used to negotiate channeling between a Cisco and non-Cisco switch? A. PAgP B. DTP C. VTP D. LACP
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| A8: | Answer D is correct. LACP is used to negotiate the dynamic forming of an EtherChannel between a Cisco or non-Cisco switch and another non-Cisco switch. Answer A is incorrect because PAgP is proprietary to Cisco. Answer B is incorrect because DTP, a Cisco-proprietary protocol, is used to dynamically form trunks between two switches. Answer C is incorrect because VTP, a Cisco-proprietary protocol, shares VLAN information across trunk ports. |
| Question 9 | When you're using Root Guard and a port receives a BPDU with a better path to the root, what happens to the port? A. The port is marked as inconsistent and disabled. B. The port is moved to a forwarding state. C. The port is kept in the current state. D. The port is placed in a discarding state.
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| A9: | Answer A is correct. When configured, if a Root Guard port receives a BPDU with a better path to the root, the port is disabled and the BPDU information is ignored. Answer B would be true if Root Guard were disabled. Answer C is incorrect because the port changes states. Answer D is incorrect because the port is disabled (shut down), not partially enabled, as in a discarding (blocking) state. |
| Question 10 | Which STP feature detects Layer 1 unidirectional connections and disables the connection, even if it is part of an EtherChannel? A. Loop Guard B. Root Guard C. UDLD D. PortFast
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| A10: | Answer C is correct. UDLD can detect unidirectional connections and disable them. One advantage that UDLD has over Loop Guard is that UDLD disables the particular connection, whereas Loop Guard disables the entire channel, making answer A incorrect. Answer B is incorrect because Root Guard is used to force a particular port to be a designated port, ensuring that the switch it is connected to doesn't become a root switch. Answer D is incorrect because the PortFast feature is used to place a nonswitch port into a forwarding state and remove it from the STP topology. |
