CompTIA Network+ Network+ Ethernet Switching and VLANs 3

Question 1

What is the default VLAN on most Cisco switches, and which VLAN should NOT be used for user data as a security best practice?

Accepted Answer

VLAN 1; avoid VLAN 1

Answer

VLAN 1 is the default VLAN on Cisco switches; best practice dictates moving user data off VLAN 1 to reduce attack surface since many management protocols use it by default.

Question 2

Which STP variant significantly reduces convergence time by introducing Rapid Spanning Tree Protocol?

Accepted Answer

IEEE 802.1W

Answer

IEEE 802.1W defines Rapid Spanning Tree Protocol (RSTP), which reduces convergence time from 30-50 seconds (classic STP) to a few seconds.

Question 3

A switch port connected to a workstation should have which STP feature enabled to prevent it from ever becoming a root port?

Accepted Answer

PortFast

Answer

PortFast immediately transitions an access port to the forwarding state, bypassing listening and learning states — appropriate only for ports connected to end devices, not other switches.

Question 4

What mechanism prevents a PortFast-enabled port from causing switching loops if a rogue switch is connected?

Accepted Answer

BPDU guard

Answer

BPDU guard disables a PortFast port if it receives a BPDU, preventing a rogue switch from disrupting the STP topology.

Question 5

Which inter-VLAN routing method uses a single physical link between the router and switch, with multiple logical sub-interfaces?

Accepted Answer

Router on a stick

Answer

Router on a stick uses one physical trunk link with sub-interfaces on the router — each sub-interface handles routing for a different VLAN.

CompTIA Practice Test

CompTIA Practice Test

CompTIA Network+ Network+ Ethernet Switching and VLANs 3