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Network Access — CCNA practice questions

Domain 2 of the Cisco CCNA (200-301) exam. 420 questions on this domain in the full bank — here are four free samples with answers and explanations.

Question 1 · Difficulty 3/5

Which VLAN is assigned to all switch ports by default?
  1. VLAN 1
  2. VLAN 10
  3. VLAN 100
  4. VLAN 1002
Show answer & explanation

Correct answer: A

VLAN 1
VLAN 1 is the default VLAN on Cisco switches, and all ports belong to it initially. VLAN 10 and VLAN 100 are user-defined VLANs. VLAN 1002 is a Cisco-reserved VLAN used for legacy Token Ring and FDDI, and cannot be assigned to Ethernet ports.

Question 2 · Difficulty 3/5

What encapsulation method is used for VLAN tagging on modern standard Cisco trunk links?
  1. ISL (Inter-Switch Link)
  2. 802.1Q
  3. 802.1ad (Q-in-Q)
  4. 802.1X
Show answer & explanation

Correct answer: B

802.1Q
IEEE 802.1Q is the current industry-standard VLAN tagging encapsulation used on trunk links, including modern Cisco switches. ISL was a Cisco-proprietary alternative that has been deprecated and is no longer supported on current platforms. 802.1ad (Q-in-Q) and 802.1X are related IEEE standards but serve different purposes—double-tagging and port-based authentication, respectively.

Question 3 · Difficulty 4/5

What is the primary consequence of a native VLAN mismatch on an 802.1Q trunk link?
  1. Untagged frames are forwarded into the wrong VLAN, causing traffic misdelivery
  2. The trunk link is immediately brought down by CDP
  3. All tagged frames are dropped until the mismatch is resolved
  4. Spanning Tree Protocol places both ports into blocking state
Show answer & explanation

Correct answer: A

Untagged frames are forwarded into the wrong VLAN, causing traffic misdelivery
When the native VLAN differs on each end of a trunk, untagged frames arriving on one side are placed into the locally configured native VLAN, which may be a completely different VLAN than the sender intended. This misroutes traffic and breaks reachability for devices relying on the native VLAN. CDP/LLDP will also log mismatch warnings, but the link itself stays up.

Question 4 · Difficulty 2/5

Which protocol is Cisco proprietary for neighbor discovery?
  1. LLDP
  2. CDP
  3. ARP
  4. NDP
Show answer & explanation

Correct answer: B

CDP
CDP is Cisco proprietary. LLDP is vendor-neutral. ARP and NDP resolve addresses, not discover neighbors.

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