N10-009 Networking Concepts Practice Test 6 — 15 Questions

Question 1

Which transport layer protocol is used by VoIP and streaming video because it provides low latency and does not require retransmission?

Accepted Answer

UDP. VoIP and streaming video use UDP (User Datagram Protocol) because it is connectionless and provides low-latency transmission without retransmission of lost packets. This is critical for real-time applications where a slight delay is more disruptive than occasional packet loss.

Answer

TCP

Answer

ICMP

Answer

IGMP

Question 2

A client obtains an IP address from a DHCP server but cannot resolve hostnames. The client can ping the default gateway and external IP addresses successfully. What is the most likely cause?

Accepted Answer

DNS server misconfiguration. The client can ping external IP addresses and the default gateway, confirming that IP connectivity and routing are functional. However, the inability to resolve hostnames points directly to a DNS resolution failure, which occurs when the DNS server address is misconfigured or unreachable. Since DHCP provided the IP address, the DNS server setting is likely incorrect or missing in the DHCP scope.

Answer

Incorrect subnet mask

Answer

Default gateway not set

Answer

Firewall blocking DNS

Question 3

Which IPv6 address type is used for one-to-many communication and is similar to an IPv4 multicast address?

Accepted Answer

Multicast. IPv6 multicast addresses (FF00::/8) are designed for one-to-many communication, where a single packet is delivered to multiple interfaces that have joined the multicast group. This directly parallels the behavior of IPv4 multicast addresses (224.0.0.0/4), making option A correct.

Answer

Anycast

Answer

Unicast

Answer

Broadcast

Question 4

A client and server are establishing a TCP connection. The client sends a SYN segment to the server. The server responds with a SYN-ACK segment. What is the next segment in the handshake?

Accepted Answer

ACK. The TCP three-way handshake requires the client to acknowledge the server's SYN-ACK by sending an ACK segment. This completes the handshake, establishing a full-duplex connection with synchronized sequence numbers. Without this final ACK, the server remains in a half-open state, unable to begin data transmission.

Answer

RST

Answer

FIN

Answer

SYN

Question 5

Which of the following network devices operates primarily at Layer 2 of the OSI model and uses MAC addresses to forward data?

Accepted Answer

Switch. A switch operates primarily at Layer 2 (Data Link layer) of the OSI model, forwarding frames based on destination MAC addresses. It builds a MAC address table by learning source MAC addresses from incoming frames and uses this table to make forwarding decisions, reducing collision domains and improving network efficiency.

Answer

Hub

Answer

Router

Answer

Firewall

Question 6

Which of the following network topologies connects each node to exactly two other nodes, forming a closed loop?

Accepted Answer

Ring. In a ring topology, each node is connected to exactly two neighbors, forming a closed loop where data travels in one direction (or sometimes dual-ring for redundancy). This is the only topology among the options that inherently creates a circular path with each node having exactly two connections.

Answer

Star

Answer

Bus

Answer

Mesh

Question 7

At which layer of the OSI model does a switch that uses MAC addresses to forward frames operate?

Accepted Answer

Layer 2. A switch that uses MAC addresses to forward frames operates at Layer 2 (Data Link layer) of the OSI model. Layer 2 is responsible for node-to-node data transfer and error detection, using MAC addresses as the addressing scheme. The switch builds a MAC address table by learning source MAC addresses from incoming frames and then forwards frames based on the destination MAC address, making forwarding decisions at this layer.

Answer

Layer 1

Answer

Layer 3

Answer

Layer 4

Question 8

Which IPv6 address is reserved for loopback?

Accepted Answer

::1. The IPv6 loopback address is ::1 (equivalent to 127.0.0.1 in IPv4). It is used by a host to send traffic to itself without any physical network interface involvement, as defined in RFC 4291. This address is not routable and should never appear outside the host.

Answer

::

Answer

127.0.0.1

Answer

2000::/3

Question 9

Which of the following is a characteristic of a Layer 2 broadcast domain?

Accepted Answer

Broadcast frames are forwarded to all ports within the domain.. A Layer 2 broadcast domain consists of all devices that receive a broadcast frame sent by any device within that domain. Switches forward broadcast frames (destination MAC FF:FF:FF:FF:FF:FF) out all ports except the ingress port, ensuring every device in the same VLAN or collision-free segment sees the broadcast. This is why option C is correct.

Answer

Devices can communicate using MAC addresses alone.

Answer

All devices must be on the same IP subnet.

Answer

Routers are required to communicate between devices in the same domain.

Question 10

A network switch forwards frames based on which address?

Accepted Answer

MAC address. A network switch operates at Layer 2 (Data Link Layer) of the OSI model and uses MAC addresses to make forwarding decisions. When a frame arrives, the switch examines the destination MAC address, looks it up in its MAC address table (CAM table), and forwards the frame only to the port associated with that MAC address, reducing collision domains and improving network efficiency.

Answer

IP address

Answer

Port number

Answer

Domain name

Question 11

Which of the following best describes a broadcast domain?

Accepted Answer

All devices that can receive a broadcast frame from any other device in the network segment. A broadcast domain is defined as the set of all devices that can receive a broadcast frame (destination MAC FF:FF:FF:FF:FF:FF) sent by any other device within the same network segment. This boundary is typically enforced by Layer 3 devices like routers, which do not forward broadcast frames, whereas Layer 2 switches forward broadcasts out all ports except the receiving port within the same VLAN.

Answer

All devices connected to the same switch

Answer

All devices that share the same IP subnet

Answer

All devices that have the same MAC address prefix

Question 12

A network administrator is designing a small office network with 40 workstations. The design must ensure that a single cable failure only affects the connected workstation. Which logical topology should the administrator implement?

Accepted Answer

Star. A star topology connects each workstation directly to a central switch or hub, so a cable failure only affects the single connected workstation, not the rest of the network. This meets the requirement for fault isolation at the workstation level, which is the core design goal in a small office with 40 devices.

Answer

Ring

Answer

Bus

Answer

Mesh

Question 13

At which OSI layer does a router primarily operate to make forwarding decisions based on IP addresses?

Accepted Answer

Layer 3 (Network). A router primarily operates at Layer 3 (Network) of the OSI model because it uses logical IP addresses (e.g., IPv4 or IPv6) to make forwarding decisions. The router examines the destination IP address in the packet header, performs a longest-prefix match against its routing table, and determines the next-hop interface. This layer is responsible for end-to-end delivery and path selection across multiple networks.

Answer

Layer 1 (Physical)

Answer

Layer 2 (Data Link)

Answer

Layer 4 (Transport)

Question 14

Which device operates at Layer 1 (Physical) of the OSI model and regenerates electrical signals to extend the distance of a network segment?

Accepted Answer

Hub. A hub operates at Layer 1 (Physical) of the OSI model. It receives incoming electrical signals on one port and regenerates (repeats) those signals out to all other ports, effectively extending the physical reach of a network segment. Unlike switches or routers, it performs no frame inspection or forwarding decisions.

Answer

Switch

Answer

Router

Answer

Bridge

Question 15

A network administrator has configured a switch with four VLANs: VLAN 10, 20, 30, and 99 (native). The switch is connected to a router via an 802.1Q trunk link. The router has subinterfaces for VLANs 10, 20, and 30, each with an IP address. VLAN 99 is used for management and does not have a router subinterface. How many Layer 3 broadcast domains exist in this network?

Accepted Answer

3. A Layer 3 broadcast domain corresponds to a routed IP subnet. Without a router subinterface, VLAN 99 has no Layer 3 termination, so only VLANs 10, 20, and 30 (with subinterfaces) form separate broadcast domains. Thus, there are 3 Layer 3 broadcast domains.

Answer

1

Answer

2

Answer

4