CCNA Plan

Network Access: practice questions

5 original questions · 0 editor-approved · every choice explained.

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Blueprint-mapped questions with full rationales for every choice.

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Network AccessDifficulty 2/5

Two switches are connected by an 802.1Q trunk. Switch A has native VLAN 1, switch B has native VLAN 99. What is the result?

  1. AThe trunk fails to form
  2. BCDP reports a native VLAN mismatch and untagged frames leak between VLAN 1 and VLAN 99
  3. CAll VLANs are tagged, so nothing changes
  4. DSTP blocks the trunk permanently
Show answer and rationale

Correct: B. 802.1Q sends native-VLAN frames untagged. With mismatched native VLANs, each switch places the other's untagged frames into a different VLAN, effectively bridging VLAN 1 and 99, and CDP logs a mismatch warning. The trunk still comes up.

  • A — The trunk forms; the mismatch is a configuration error, not a trunk-negotiation failure.
  • C — The native VLAN is exactly the VLAN that is not tagged.
  • D — STP may detect inconsistency on PVST+ but does not permanently block by default in this scenario.
Network AccessDifficulty 3/5

Four switches run Rapid PVST+ with default priority. Which switch becomes the root bridge?

  1. AThe switch with the highest MAC address
  2. BThe switch with the most ports
  3. CThe switch with the lowest MAC address
  4. DThe switch that boots first
Show answer and rationale

Correct: C. With equal priorities (32768 + VLAN ID), the bridge ID tie-breaker is the lowest MAC address. Set a lower priority on your intended root rather than relying on MAC.

  • A — Lowest, not highest, bridge ID wins.
  • B — Port count is irrelevant to the election.
  • D — Boot order does not affect the deterministic election.
Network AccessDifficulty 3/5

An engineer configures channel-group 1 mode active on switch A and channel-group 1 mode auto on switch B. What happens?

  1. AA static EtherChannel forms
  2. BAn LACP EtherChannel forms
  3. CA PAgP EtherChannel forms
  4. DNo EtherChannel forms because active is LACP and auto is PAgP
Show answer and rationale

Correct: D. 'active' and 'passive' are LACP modes; 'desirable' and 'auto' are PAgP modes. Mixing protocols prevents negotiation, so the bundle never forms and the links operate individually (STP may block one).

  • B — LACP needs active/active or active/passive on both sides.
  • C — PAgP needs desirable/desirable or desirable/auto.
  • A — Static requires mode on at both ends.
Network AccessDifficulty 2/5

On which type of port should PortFast be enabled?

  1. AAccess ports connected to end hosts
  2. BRoot ports only
  3. CAll ports, to speed up convergence
  4. DTrunk ports to other switches
Show answer and rationale

Correct: A. PortFast moves an access port straight to forwarding, which is safe only where no switch (and thus no loop) can appear. Enabling it toward switches risks loops; BPDU Guard is usually paired with it.

  • D — A trunk to a switch can create a loop during the forwarding delay.
  • B — Root ports are determined by STP; PortFast is an admin setting for edge ports.
  • C — Blanket enablement defeats loop prevention.
Network AccessDifficulty 2/5

In a Cisco lightweight wireless architecture, which protocol carries control and data between an AP and the WLC?

  1. ALWAPP
  2. BCAPWAP
  3. CRADIUS
  4. D802.1Q
Show answer and rationale

Correct: B. Lightweight APs tunnel to the wireless LAN controller using CAPWAP (control and data channels). This is the split-MAC model.

  • A — LWAPP was the predecessor, replaced by CAPWAP.
  • C — RADIUS is used for AAA, not AP–WLC tunneling.
  • D — 802.1Q is VLAN tagging on wired trunks.

Primary references

  1. CCNA Exam v1.1 (200-301) Exam Topics — Cisco Systems · primary · retrieved 2026-09-21, verified 2026-09-21