CCNA Network Infrastructure and Connectivity Practice Test 2 — 15 Questions

Question 1

Which statement correctly describes the purpose of ARP in an IPv4 network?

Accepted Answer

It maps an IPv4 address to a MAC address on the local segment. ARP maps a known IPv4 address to a Layer 2 MAC address on the local network segment. That allows the sender to build the Ethernet frame needed for local delivery.

Answer

It maps a MAC address to a DNS hostname

Answer

It advertises routes between routers

Answer

It negotiates trunk encapsulation between switches

Question 2

What is the purpose of the default gateway on a host?

Accepted Answer

It forwards traffic to remote networks. The default gateway is the local router interface a host uses when sending traffic to destinations outside its own subnet.

Answer

It assigns IP addresses dynamically to the host

Answer

It resolves hostnames into IP addresses

Answer

It encrypts traffic between hosts

Question 3

An IPv6 LAN is using SLAAC. Which message allows hosts to learn the default gateway and on-link prefix?

Accepted Answer

Router Advertisement. In an IPv6 LAN using SLAAC (Stateless Address Autoconfiguration), hosts learn the default gateway and on-link prefix from Router Advertisement (RA) messages sent by routers. Neighbor Solicitation (NS) is used for address resolution and Duplicate Address Detection (DAD), not for learning gateway/prefix. DHCPv6 Solicit is part of stateful DHCPv6, not SLAAC. ICMP Echo Reply is a simple reachability test and provides no configuration information.

Answer

Neighbor Solicitation

Answer

DHCPv6 Solicit

Answer

ICMP Echo Reply

Question 4

Match the network management function to its primary purpose.

Accepted Answer

SNMP: Monitors network devices and collects statistics. Syslog centralizes log collection from network devices for monitoring and troubleshooting. SNMP monitors network devices and collects statistics. NetFlow analyzes network traffic flows and bandwidth usage. NTP synchronizes clocks across network devices to ensure consistent timestamps.

Question 5

Match each Ethernet or switching term to its most accurate description.

Accepted Answer

A 48-bit hardware address burned into the NIC used for Layer 2 identification. This is a matching question where each term must be paired with its correct description. The correct matches are: MAC address → 48-bit hardware address burned into the NIC; Switch → network device that forwards frames based on MAC addresses; VLAN → logical segmentation of a switch into separate broadcast domains; Trunk → link that carries multiple VLANs between switches; STP → protocol that prevents loops in a redundant switched network; ARP cache → table that stores IP-to-MAC address mappings. The explanation provided earlier only addressed the MAC address pair; the full set of matches is defined in the pbq_config.

Answer

A logical grouping of ports that isolates broadcast domains within a switch

Answer

A link that carries traffic for multiple VLANs using 802.1Q tagging

Answer

A protocol that prevents loops in a redundant switched network

Question 6

Match each IP service or protocol to its most accurate purpose.

Accepted Answer

DNS: Resolves domain names to IP addresses. DNS translates domain names into IP addresses, enabling users to access resources using human-readable names. DHCP automatically assigns IP addresses and other network parameters to clients, reducing manual configuration. NAT translates private IP addresses to public IP addresses for internet access, conserving public IP space. ICMP is used for error reporting and diagnostic functions like ping and traceroute.

Question 7

Match each subnetting term to its most accurate meaning.

Accepted Answer

Subnet mask: A 32-bit value that distinguishes the network portion from the host portion of an IP address.. The subnet mask is a 32-bit value used in IPv4 networking to distinguish the network portion from the host portion of an IP address. Option A correctly defines it. Option B incorrectly says it identifies the broadcast address – the broadcast address is computed using the subnet mask, not the mask itself. Option C incorrectly says it represents the number of hosts – that is determined by the host bits. Option D incorrectly says it identifies the network address – the network address is also computed using the mask, but the mask itself is not the network address. Thus, only option A is accurate.

Answer

Subnet mask: A 32-bit value that identifies the broadcast address of a subnet.

Answer

Subnet mask: A 32-bit value that represents the number of hosts available in a subnet.

Answer

Subnet mask: A 32-bit value that identifies the network address of a subnet.

Question 8

Which type of IPv4 address is assigned to a device interface?

Accepted Answer

Host address. A host address is a usable IPv4 address assigned to a device interface. The network address (first address) and broadcast address (last address) are reserved and cannot be assigned to a device. The loopback address (127.0.0.1) is reserved for internal testing and is not assigned to a physical device interface.

Answer

Network address

Answer

Broadcast address

Answer

Loopback address

Question 9

Which two statements accurately describe the role of a default gateway on an IPv4 host?

Accepted Answer

It is the next-hop path used for destinations outside the local subnet.. A default gateway gives the host a next hop for traffic that is not destined for the local subnet. In plain language, it is the local router or Layer 3 interface the host uses when the destination is somewhere else. The host still needs its IP address and subnet mask to decide what is local, but once it decides something is remote, the default gateway becomes the path out.

The most common mistake is treating the default gateway like a DNS server or assuming it replaces the subnet mask. It does not. The two correct answers are the ones focused on off-subnet forwarding and the fact that the gateway must be reachable on the host’s own local network.

Answer

It replaces the need for a subnet mask.

Answer

It is the same thing as a DNS server.

Answer

It is used only for broadcast traffic.

Question 10

What is the most accurate role of DNS in a network?

Accepted Answer

DNS - Resolves domain names to IP addresses. DNS resolves domain names to IP addresses, allowing users to reach hosts by name. DHCP assigns IP addresses dynamically, NTP synchronizes clocks, and Syslog centralizes logs. The only accurate DNS role among the options is A.

Answer

DNS - Assigns IP addresses to devices dynamically

Answer

DNS - Synchronizes clocks across network devices

Answer

DNS - Provides secure remote access to network devices

Question 11

A subnet must support at least 126 usable IPv4 host addresses. Which prefix is the longest that meets the requirement?

Accepted Answer

/25. A /25 is the smallest valid answer. In practical terms, a /25 provides 128 total addresses. After subtracting the network and broadcast addresses, 126 usable hosts remain. A /26 would be too small because it supports only 62 usable hosts.

This is a typical minimum-prefix question. The goal is to choose the smallest subnet that satisfies the host requirement without wasting more address space than necessary.

Answer

/26

Answer

/24

Answer

/27

Question 12

Match each IPv4-related concept to its most accurate role.

Accepted Answer

IPv4 address. The IPv4 address uniquely identifies a host on an IP network. The subnet mask distinguishes the network and host portions of the address, determining the local subnet. The default gateway is the router interface that forwards traffic to destinations outside the local subnet. The DNS server resolves domain names to IP addresses, enabling name-based communication. Each concept plays a distinct and essential role in IPv4 networking.

Question 13

Match each protocol or service to its primary function.

Accepted Answer

HTTP: Transfers web pages and resources. HTTP (Hypertext Transfer Protocol) is used for transferring web pages and resources from a web server to a client browser. FTP (File Transfer Protocol) enables file transfers between a client and a server over a network. SMTP (Simple Mail Transfer Protocol) is the standard protocol for sending email messages from a client to a server or between mail servers. SSH (Secure Shell) provides encrypted remote login and command execution, replacing insecure protocols like Telnet. Each protocol serves a distinct role in network communication.

Question 14

A network engineer is troubleshooting a link between two Cisco switches that are connected via a 1000BASE-LX SFP transceiver. Hosts on VLAN 10 on Switch A cannot ping the default gateway on Switch B. The interface on Switch A is up, but the engineer notices CRC errors incrementing. What should the engineer do to resolve this issue?

Accepted Answer

Use a mode-conditioning patch cable between the SFP and the fiber patch panel. The 1000BASE-LX SFP transceiver operates at 1310 nm over single-mode fiber (SMF). When connected to multimode fiber (MMF), the larger core diameter causes excessive modal dispersion, leading to CRC errors. A mode-conditioning patch cable (mode-conditioning patch cord) launches the laser off-center into the MMF core, reducing differential mode delay and restoring proper signal integrity. This is a known Cisco best practice for LX transceivers on MMF links.

Answer

Replace the SFP with a 1000BASE-SX transceiver

Answer

Configure the same VLAN on both switch interfaces

Answer

Replace the fiber cable with a single-mode fiber cable

Question 15

Drag and drop the cable types, transceivers, and diagnostic commands on the left to the correct descriptions or specifications on the right.

Accepted Answer

Straight-through cable: Connects PC to switch. Straight-through cables connect dissimilar devices (e.g., PC to switch), while crossover cables connect similar devices (e.g., switch to switch). Rollover cables (console cables) are used for console access. SFP (Small Form-factor Pluggable) is a hot-swappable transceiver used for fiber or copper connections.