ACA Networking Fundamentals 3 — Questions and Answers
Question 1: Which IEEE standard defines the Spanning Tree Protocol used to prevent loops in a switched network?
- IEEE 802.1Q
- IEEE 802.1D (Correct answer)
- IEEE 802.3
- IEEE 802.11
Correct answer: IEEE 802.1D
IEEE 802.1D defines the original Spanning Tree Protocol (STP), which blocks redundant paths to create a loop-free Layer 2 topology.
Question 2: What is the purpose of a VLAN trunk port?
- To connect a switch to an end-user device on a single VLAN
- To carry traffic for multiple VLANs between switches using 802.1Q tagging (Correct answer)
- To block broadcast domains from propagating
- To assign IP addresses to VLAN members
Correct answer: To carry traffic for multiple VLANs between switches using 802.1Q tagging
A trunk port carries tagged frames for multiple VLANs between switches or between a switch and a router, using IEEE 802.1Q encapsulation.
Question 3: What does CSMA/CD stand for and where is it used?
- Carrier Sense Multiple Access / Collision Detection – used in traditional Ethernet (Correct answer)
- Carrier Sense Multiple Access / Collision Detection – used in Wi-Fi
- Channel Switching Multiple Access / Collision Delay – used in Token Ring
- Circuit Switched Multiple Access / Collision Detection – used in fiber optics
Correct answer: Carrier Sense Multiple Access / Collision Detection – used in traditional Ethernet
CSMA/CD is the media access control method used in traditional half-duplex Ethernet, where stations detect collisions and retransmit after a random back-off.
Question 4: Which protocol dynamically assigns IP addresses, subnet masks, gateways, and DNS server information to hosts?
- TFTP
- SNMP
- DHCP (Correct answer)
- NTP
Correct answer: DHCP
DHCP (Dynamic Host Configuration Protocol) automatically provides hosts with IP addressing parameters, eliminating the need for manual static configuration.
Question 5: What is the broadcast address for the subnet 192.168.10.64/26?
- 192.168.10.95
- 192.168.10.127 (Correct answer)
- 192.168.10.191
- 192.168.10.255
Correct answer: 192.168.10.127
The /26 subnet starting at 192.168.10.64 has a block size of 64; the broadcast address is 192.168.10.64 + 63 = 192.168.10.127.
Question 6: What function does NAT (Network Address Translation) primarily serve?
- Encrypts all traffic leaving the network
- Translates private IP addresses to a public IP for Internet communication (Correct answer)
- Assigns MAC addresses to devices
- Filters packets based on Layer 4 port numbers
Correct answer: Translates private IP addresses to a public IP for Internet communication
NAT allows multiple devices using private RFC 1918 addresses to share one or more public IP addresses when communicating over the Internet.
Question 7: Which cable type uses light pulses to transmit data and is immune to electromagnetic interference?
- Cat 6 UTP
- Coaxial
- Fiber optic (Correct answer)
- STP (Shielded Twisted Pair)
Correct answer: Fiber optic
Fiber optic cables transmit data as light through glass or plastic strands, making them immune to EMI and capable of much longer distances than copper.
ACA Networking Fundamentals 3
Which IEEE standard defines the Spanning Tree Protocol used to prevent loops in a switched network?