200-301 Cisco Certified Network Associate (CCNA) Exam Dumps and Practice Test Questions Set 1 Q1-20

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Question 1: 

A network engineer is configuring OSPF on a multi-area network. Router R1 is in Area 0, and Router R2 is in Area 1. The network between them is a serial link. After configuring OSPF, the engineer notices that R1 does not show R2’s routes in its routing table. What could be the reason?

A) R1 and R2 are using different OSPF process IDs
B) The serial link is down
C) R2’s interface is not assigned to any OSPF area
D) OSPF requires BGP to be configured first

Answer: C

Explanation: 

OSPF requires that interfaces participating in OSPF be explicitly configured with an areA) If R2’s serial interface is not assigned to Area 1, R1 will not learn routes from R2. Ensuring proper area assignment resolves this issue.

In this scenario, Router R1 is in Area 0 and Router R2 is in Area 1, connected via a serial link. After configuring OSPF, R1 does not see R2’s routes in its routing table. One possible reason could be the OSPF process ID mismatch, as in option A) While each router can have a different OSPF process ID locally, this does not affect OSPF neighbor formation or route exchange. Therefore, this is unlikely to be the cause of the missing routes.

Option B suggests that the serial link is down. If the link were physically or administratively down, R1 would not even establish an OSPF adjacency with R2. In that case, the engineer would likely notice the interface state as down, and no OSPF neighbor would appear.

Option C, where R2’s interface is not assigned to any OSPF area, is the most probable cause. OSPF requires that every interface participating in OSPF be explicitly configured with an areA) If the interface connecting to R1 is not assigned to Area 1, R2 will not advertise its routes to R1, and the OSPF adjacency may not fully form or exchange routes.

Option D is incorrect because OSPF is a standalone interior gateway protocol and does not require BGP to be configureD) The solution is to ensure that R2’s interface on the serial link is assigned to Area 1 so that OSPF can properly exchange routes between the areas.

This explains why the missing routes occur and highlights the importance of proper area configuration in OSPF.

Question 2: 

A network has VLAN 10 for accounting and VLAN 20 for HR. Switch S1 is connected to Router R1 via a trunk port. Hosts in VLAN 10 cannot communicate with hosts in VLAN 20. What configuration is required on R1?

A) Enable RIP on R1
B) Configure subinterfaces on R1 with dot1q encapsulation for VLAN 10 and VLAN 20
C) Assign IP addresses to the switch interfaces
D) Configure static routes on the switch

Answer: B

Explanation: 

Inter-VLAN routing requires a Layer 3 device to route traffic between VLANs. Subinterfaces with 802.1Q encapsulation on the router allow traffic from multiple VLANs to be routed properly.

In this network, VLAN 10 is for accounting and VLAN 20 is for HR, with Switch S1 connected to Router R1 via a trunk port. Hosts in VLAN 10 are unable to communicate with hosts in VLAN 20, indicating that inter-VLAN routing is not configureD)

Option A suggests enabling RIP on R1. While RIP is a routing protocol, simply enabling it will not allow communication between VLANs unless the router already has interfaces in each VLAN. RIP is primarily used for exchanging routes between different networks, not for directly routing between VLANs on the same router.

Option B is the correct solution. Inter-VLAN routing requires a Layer 3 device, such as a router, to route traffic between different VLANs. On R1, subinterfaces must be created for each VLAN, with 802.1Q encapsulation configureD) Each subinterface is assigned an IP address corresponding to its VLAN. This setup allows the router to receive tagged traffic from the trunk port and route it appropriately between VLAN 10 and VLAN 20, enabling hosts in different VLANs to communicate.

Option C suggests assigning IP addresses to the switch interfaces. While assigning IPs may allow management access to the switch, it does not enable inter-VLAN routing because Layer 2 switches cannot route traffic between VLANs by themselves.

Option D suggests configuring static routes on the switch. Layer 2 switches do not support routing between VLANs without a Layer 3 device, so static routes on the switch will not resolve the issue.Therefore, configuring subinterfaces with dot1q encapsulation on R1 is necessary for proper inter-VLAN communication.

Question 3: 

Which of the following is a characteristic of TCP that distinguishes it from UDP?

A) Connectionless
B) Low latency
C) Reliable delivery with sequencing
D) Broadcast transmission

Answer: C

Explanation: 

TCP is connection-oriented and ensures reliable delivery, sequencing, and error checking. UDP is connectionless and does not guarantee delivery or ordering.

TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) are both transport layer protocols, but they have fundamental differences that affect how data is transmitted across a network.

Option A, connectionless, is actually a characteristic of UDP, not TCP. UDP does not establish a connection before sending data and simply transmits packets independently, making it faster but less reliable. TCP, in contrast, is connection-oriented, requiring a three-way handshake before data transfer begins to ensure a stable connection.

Option B, low latency, is often associated with UDP because it avoids the overhead of connection setup and error checking. TCP, due to its mechanisms for reliability and sequencing, introduces slightly higher latency, which is a trade-off for accurate and complete delivery.

Option C, reliable delivery with sequencing, is the distinguishing feature of TCP. TCP ensures that all segments of data are delivered to the destination correctly and in the order they were sent. It uses acknowledgments, retransmissions, and sequence numbers to provide reliability. This guarantees that applications like file transfers, email, and web browsing receive complete and ordered datA)

Option D, broadcast transmission, is not a feature of TCP. TCP communicates between two endpoints in a unicast manner. UDP can support broadcast or multicast transmissions, which is useful for applications like streaming or network discovery.Thus, the key characteristic that sets TCP apart from UDP is its reliable delivery with sequencing, making it suitable for applications where data integrity is critical.

Question 4: 

A network engineer is configuring an access point to use WPA3-Personal for wireless security. Which key feature is unique to WPA3 compared to WPA2?

A) Pre-shared key authentication
B) Enhanced encryption using SAE (Simultaneous Authentication of Equals)
C) WEP compatibility
D) Open authentication without passwords

Answer: B

Explanation: 

WPA3 introduces SAE, which replaces the WPA2 pre-shared key handshake for stronger security and protection against offline dictionary attacks.

When configuring wireless security, WPA3-Personal offers several improvements over WPA2. One of the key differences lies in how authentication and encryption are handleD)

Option A, pre-shared key authentication, is a feature of both WPA2 and WPA3. Both standards allow users to connect using a shared password, so this is not unique to WPA3. While WPA3 still uses a password-based method, it strengthens the process through a more secure handshake mechanism.

Option B, enhanced encryption using SAE (Simultaneous Authentication of Equals), is the feature that distinguishes WPA3 from WPA2. SAE replaces the WPA2 pre-shared key handshake and provides stronger protection against offline dictionary attacks. It allows devices to establish a secure connection even if an attacker captures the handshake, because SAE ensures that each authentication attempt requires active participation from both parties. This prevents attackers from using captured data to guess passwords later.

Option C, WEP compatibility, is not relevant to WPA3. WEP is an outdated and insecure protocol that has been deprecated due to severe vulnerabilities. WPA3 does not aim to maintain compatibility with WEP.Option D, open authentication without passwords, refers to networks that do not require a password, such as public hotspots. WPA3 does not eliminate the need for passwords in WPA3-Personal mode; instead, it enhances security for password-based connections.Therefore, the unique and defining feature of WPA3 is its use of SAE for stronger, more secure authentication and encryption.

Question 5: 

A router receives a packet with a destination IP address not in its routing table. What will the router do?

A) Drop the packet
B) Forward it to a default route if configured
C) Send an ICMP unreachable message if no default route exists
D) All of the above

Answer: D

Explanation: 

If a destination is unknown, a router will check for a default route. If no default route exists, it will drop the packet and generate an ICMP unreachable message.

When a router receives a packet, it checks the destination IP address against its routing table to determine the next hop. If the destination address is not found in the routing table, the router follows specific steps to handle the packet.

Option A states that the router will drop the packet. This is partially correct. If the router has no way to forward the packet, and no default route exists, it will indeed drop the packet to prevent it from circulating indefinitely.

Option B mentions forwarding the packet to a default route if configureD) Many routers have a default route set, often called a “gateway of last resort.” If a default route exists, the router will forward the packet through this path, allowing traffic to reach networks not explicitly listed in the routing table.

Option C indicates sending an ICMP unreachable message if no default route exists. When a packet cannot be delivered and there is no default route, the router may generate an ICMP destination unreachable message back to the source, notifying it that the destination is unreachable.

Option D, all of the above, is correct because all the previous actions describe how routers handle packets with unknown destinations under different circumstances. The router first looks for a match in the routing table, forwards the packet via a default route if available, or drops the packet and optionally sends an ICMP unreachable message when no route exists. This ensures proper network behavior and informs the source of delivery issues.

Question 6: 

What is the purpose of HSRP in a network?

A) Load balancing across routers
B) Provide gateway redundancy for hosts
C) Encrypt routing updates
D) Reduce broadcast traffic

Answer: B

Explanation: 

HSRP (Hot Standby Router Protocol) allows multiple routers to appear as a single virtual default gateway for hosts, ensuring network continuity if one router fails.

HSRP, or Hot Standby Router Protocol, is used in networks to increase the reliability of the default gateway for hosts. Its main purpose is to provide redundancy, ensuring that if one router fails, another can take over without interrupting network connectivity.

Option A, load balancing across routers, is not the function of HSRP. HSRP does not distribute traffic between multiple routers; instead, it designates one router as active and another as standby, with only the active router handling traffic at a given time. Other protocols, like GLBP (Gateway Load Balancing Protocol), are designed for load balancing.

Option B, providing gateway redundancy for hosts, correctly describes HSRP’s purpose. By allowing multiple routers to share a single virtual IP address as the default gateway, hosts always have a reachable gateway. If the active router fails, the standby router automatically assumes the role of the active gateway, maintaining uninterrupted network access.

Option C, encrypt routing updates, is unrelated to HSRP. HSRP does not handle routing protocols or encryption of routing information; it operates at Layer 3 to manage default gateway availability.Option D, reducing broadcast traffic, is also not the goal of HSRP. While it may generate some multicast packets to communicate state changes between routers, its primary function is not to reduce broadcast traffiC)In summary, HSRP ensures continuous network access for hosts by providing a highly available virtual gateway, minimizing downtime in case of router failure.

Question 7: 

Which of the following best describes a characteristic of a Class B IP address?

A) 1–126 in the first octet
B) 128–191 in the first octet
C) 192–223 in the first octet
D) 224–239 in the first octet

Answer: B

Explanation: 

Class B IP addresses range from 128–191 in the first octet. They use a default subnet mask of 255.255.0.0.

IP addresses are divided into classes based on the value of the first octet, which helps determine the network size and default subnet mask. Understanding these classes is important for designing and managing networks effectively.

Option A states 1–126 in the first octet, which describes Class A addresses. Class A addresses are intended for very large networks and have a default subnet mask of 255.0.0.0, allowing a large number of host addresses per network.

Option B, 128–191 in the first octet, correctly identifies Class B addresses. Class B networks are designed for medium-sized organizations and use a default subnet mask of 255.255.0.0. This allows for a larger number of networks than Class A but fewer hosts per network. The first two octets define the network portion, and the last two octets define host addresses, providing up to 65,534 usable host addresses per network.

Option C, 192–223 in the first octet, corresponds to Class C addresses. Class C is typically used for small networks, with a default subnet mask of 255.255.255.0, allowing up to 254 hosts per network.Option D, 224–239 in the first octet, defines Class D addresses, which are reserved for multicast traffic rather than standard host-to-host communication.

In summary, Class B addresses are uniquely identified by having the first octet range from 128 to 191 and using a default subnet mask of 255.255.0.0, supporting medium-sized networks with a significant number of host addresses.

Question 8:

An engineer configures a router with the command ip route 0.0.0.0 0.0.0.0 192.168.1.1. What type of route is this?

A) Static default route
B) Dynamic route
C) Floating static route
D) Host route

Answer: A

Explanation: 

The command configures a static default route. The 0.0.0.0/0 network specifies all destinations, and the next-hop IP defines where unmatched traffic should be sent.

The command ip route 0.0.0.0 0.0.0.0 192.168.1.1 configures a specific type of route on a router that determines how traffic to unknown destinations is handleD)

Option A, static default route, correctly describes this configuration. The 0.0.0.0/0 network represents all possible IP addresses that do not have a more specific match in the routing table. By specifying a next-hop IP address of 192.168.1.1, the router forwards any packet that does not match a known route to that next-hop device. This provides a simple way to direct unmatched traffic, commonly used to connect to an upstream router or the internet. Since the route is manually configured and does not rely on a routing protocol, it is classified as a static route.

Option B, dynamic route, is incorrect because dynamic routes are learned and maintained automatically through routing protocols like OSPF, EIGRP, or RIP. They adjust automatically to changes in the network, unlike this manually configured route.

Option C, floating static route, is a type of static route configured with a higher administrative distance to serve as a backup, but the command shown does not specify a non-default administrative distance, so it is not a floating static route.

Option D, host route, is for a specific IP address with a subnet mask of 255.255.255.255. Since the command uses 0.0.0.0/0, it is not a host route.

Thus, this configuration is a static default route, providing a gateway of last resort for traffic to unknown destinations.

Question 9: 

Which layer of the OSI model is responsible for end-to-end delivery and error recovery?

A) Physical
B) Network
C) Transport
D) Data Link

Answer: C

Explanation: 

The Transport layer (Layer 4) ensures reliable delivery of data using mechanisms such as sequencing, acknowledgment, and retransmission (TCP).

The OSI model is a conceptual framework that standardizes the functions of a telecommunication or computing system into seven layers, each with specific responsibilities. Understanding the role of each layer helps in troubleshooting and designing networks.

Option A, the Physical layer, is responsible for the actual transmission of raw bits over a physical medium such as cables or radio waves. It deals with electrical signals, cabling, connectors, and physical topology, but it does not provide reliability, sequencing, or error recovery.

Option B, the Network layer, handles logical addressing and routing of packets between devices across different networks. While it determines the best path for data to reach its destination and manages packet forwarding, it does not guarantee end-to-end delivery or handle retransmissions if packets are lost.

Option C, the Transport layer, is responsible for end-to-end delivery and error recovery. It ensures that data sent from an application on one host is received correctly by the corresponding application on another host. Transport layer protocols, such as TCP, provide mechanisms like sequencing, acknowledgment, and retransmission to guarantee reliable delivery, detect errors, and manage flow control. UDP, another transport layer protocol, provides delivery without reliability, showing that these features are specific to certain transport protocols.

Option D, the Data Link layer, manages reliable transmission over a single physical link and handles error detection, framing, and media access control, but its scope is limited to local links, not end-to-end communication.Therefore, the Transport layer is the OSI layer responsible for ensuring reliable, end-to-end data delivery with error recovery.

Question 10: 

What is the function of CDP in a Cisco network?

A) Encrypts data between routers
B) Shares information about directly connected Cisco devices
C) Performs VLAN routing
D) Detects loops in the network

Answer: B

Explanation: 

CDP (Cisco Discovery Protocol) is a Layer 2 protocol that allows Cisco devices to share device information such as device ID, IP addresses, and interfaces with neighbors.

CDP, or Cisco Discovery Protocol, is a proprietary Layer 2 protocol used in Cisco networks to facilitate the sharing of information between directly connected devices. Its primary function is to help network administrators discover and manage Cisco devices in the network.

Option A, encrypting data between routers, is incorrect. CDP does not provide encryption or secure data transmission. Its role is limited to sharing information about devices, not protecting traffic between them. Encryption is handled by other protocols such as IPsec or SSL.

Option B, sharing information about directly connected Cisco devices, correctly describes CDP’s purpose. CDP allows devices to advertise details like device ID, IP addresses, operating system version, interface types, and VLAN information to neighboring Cisco devices. This information is helpful for troubleshooting, network mapping, and verifying connectivity between devices. Network administrators can use CDP outputs to identify the topology, connected devices, and interface configurations.

Option C, performing VLAN routing, is also incorrect. VLAN routing is handled by Layer 3 devices or Layer 3 switches using routing protocols or inter-VLAN routing configurations. CDP operates only at Layer 2 and does not forward or route traffic between VLANs.

Option D, detecting loops in the network, is unrelated to CDP. Loop detection is performed by protocols like Spanning Tree Protocol (STP), which prevents broadcast storms and ensures a loop-free Layer 2 topology.In summary, CDP’s function is to share information about directly connected Cisco devices, enabling administrators to gain visibility into the network and simplify device management and troubleshooting.

Question 11: 

A network administrator wants to prevent IP address conflicts in a subnet. Which protocol is commonly used?

A) DHCP
B) ARP
C) ICMP
D) FTP

Answer: A

Explanation: 

DHCP (Dynamic Host Configuration Protocol) dynamically assigns IP addresses to hosts and avoids conflicts by keeping track of allocated addresses.

Preventing IP address conflicts in a subnet is essential for maintaining reliable network communication. When two devices have the same IP address, it can cause connectivity issues, data loss, and network disruptions.

Option A, DHCP (Dynamic Host Configuration Protocol), is the protocol most commonly used to prevent IP conflicts. DHCP automatically assigns unique IP addresses to devices when they join the network. It keeps track of which addresses have been leased to which hosts, ensuring that no two devices receive the same IP simultaneously. DHCP can also provide additional information such as subnet mask, default gateway, and DNS servers, simplifying network management and reducing configuration errors.

Option B, ARP (Address Resolution Protocol), is used to map IP addresses to MAC addresses on a local network. While ARP helps devices communicate at Layer 2, it does not assign IP addresses or prevent conflicts. ARP cannot dynamically manage address allocation and only resolves addresses for already configured IPs.

Option C, ICMP (Internet Control Message Protocol), is used for sending error messages and operational information, such as when a host is unreachable. ICMP is useful for diagnostics and troubleshooting, for example through the ping command, but it does not assign or manage IP addresses.

Option D, FTP (File Transfer Protocol), is used for transferring files over a network and has no role in IP address management or conflict prevention.Therefore, DHCP is the protocol that ensures each device in a subnet receives a unique IP address, preventing conflicts and simplifying network administration.

Question 12:

Which routing protocol is considered classless and supports VLSM?

A) RIP v1
B) OSPF
C) IGRP
D) RIPv1

Answer: B

Explanation: 

OSPF is classless, supports Variable Length Subnet Masking (VLSM), and sends subnet mask information in its routing updates. RIPv1 and IGRP are classful protocols.

Routing protocols are used to dynamically share network information between routers, but they differ in how they handle subnetting and address classes. Understanding whether a protocol is classful or classless is important for efficient IP address allocation.

Option A, RIP v1, is a classful routing protocol. It does not include subnet mask information in its routing updates, which means it cannot support Variable Length Subnet Masking (VLSM). Networks using RIP v1 must adhere to the default classful boundaries, limiting flexibility in IP address allocation.

Option B, OSPF (Open Shortest Path First), is a classless routing protocol and fully supports VLSM. OSPF includes subnet mask information in its routing updates, allowing routers to handle subnets of varying sizes within the same network. This capability makes OSPF more efficient for large and hierarchical networks, as it enables optimized use of IP address space and more precise routing.

Option C, IGRP (Interior Gateway Routing Protocol), is also classful. Similar to RIP v1, it does not carry subnet mask information in routing updates, preventing it from supporting VLSM and limiting its ability to work efficiently with discontiguous subnets.

Option D, RIPv1, is the original version of RIP and, like RIP v1, is classful and cannot support VLSM. Its lack of subnet mask propagation makes it unsuitable for networks that require variable subnet sizes.In summary, OSPF is the routing protocol that is classless, supports VLSM, and allows more flexible and efficient IP address management compared to classful protocols like RIP v1, RIPv1, and IGRP.

Question 13: 

Which type of NAT translates multiple private IP addresses to a single public IP using different ports?

A) Static NAT
B) Dynamic NAT
C) PAT (Port Address Translation)
D) Overloading NAT

Answer: C

Explanation:

PAT, also called NAT overload, allows multiple private IP addresses to be translated to a single public IP address using unique port numbers for each session.

Network Address Translation (NAT) is used to map private IP addresses to public IP addresses, allowing internal devices to communicate with external networks like the internet while conserving public IP space. Different types of NAT handle this mapping in distinct ways.

Option A, Static NAT, provides a one-to-one mapping between a private IP and a public IP. Each internal device is assigned a specific public IP address. While this allows predictable addressing, it does not conserve public IP addresses because each internal host requires its own unique public IP.

Option B, Dynamic NAT, assigns a public IP from a pool of available addresses when an internal device initiates communication. The mapping is temporary and only lasts for the duration of the session. Dynamic NAT is more efficient than static NAT but still requires enough public IP addresses for all simultaneous internal connections.

Option C, PAT (Port Address Translation), is the correct answer. Also known as NAT overload, PAT allows multiple private IP addresses to share a single public IP address. It differentiates sessions using unique port numbers for each connection. This enables many devices on a private network to access external networks simultaneously without needing a separate public IP for each device.

Option D, Overloading NAT, is another term for PAT. It highlights the ability to “overload” a single public IP with multiple internal hosts by using different port numbers.In summary, PAT uniquely translates multiple private IPs to a single public IP using port numbers, making it the most efficient NAT method for networks with limited public addresses.

Question 14: 

Which command displays the MAC address table on a Cisco switch?

A) show ip route
B) show mac-address-table
C) show running-config
D) show arp

Answer: B

Explanation: 

The show mac-address-table command displays the MAC addresses learned by the switch along with the associated ports

In a Cisco network, switches maintain a MAC address table to map the MAC addresses of connected devices to specific switch ports. This table allows the switch to forward frames efficiently and reduces unnecessary flooding.

Option A, show ip route, is used on routers and Layer 3 switches to display the routing table. It shows the networks the device knows, the next-hop addresses, and the interfaces used to reach those networks. This command does not display MAC addresses or port associations.

Option B, show mac-address-table, is the correct command for viewing the MAC address table on a Cisco switch. It lists all the MAC addresses the switch has learned, the VLANs associated with each address, and the specific ports through which the devices are connecteD) This information is essential for troubleshooting connectivity issues, verifying port security, and understanding traffic flow within the LAN.

Option C, show running-config, displays the current configuration of the switch, including interface settings, VLAN assignments, and security configurations. While useful for configuration verification, it does not provide real-time information about learned MAC addresses.

Option D, show arp, shows the IP-to-MAC address mappings learned by the device at Layer 3. It is useful for verifying IP connectivity but does not indicate which physical switch port a device is connected to.Therefore, the show mac-address-table command is the tool used to display the MAC addresses learned by a Cisco switch and their corresponding ports.

Question 15: 

A company wants to segment its network into multiple broadcast domains. Which device should be used?

A) Hub
B) Switch
C) Router
D) Repeater

Answer: C

Explanation: 

Routers separate broadcast domains. Switches operate at Layer 2 and forward broadcasts within a VLAN, while routers perform inter-VLAN routing and isolate broadcast traffiC)

Segmenting a network into multiple broadcast domains is important for improving performance, reducing congestion, and enhancing security. Each broadcast domain limits the scope of broadcast traffic, preventing it from overwhelming the entire network.

Option A, a hub, is a basic Layer 1 device that simply repeats incoming signals to all ports. Hubs do not create separate broadcast domains; all devices connected to a hub are in the same broadcast domain, so using a hub does not help with network segmentation.

Option B, a switch, operates at Layer 2 and forwards frames based on MAC addresses. While switches can separate collision domains, all ports on the same VLAN still belong to a single broadcast domain. Without VLAN configuration, a switch does not isolate broadcast traffic, meaning broadcast frames are forwarded to all ports within the VLAN.

Option C, a router, is the correct choice for segmenting a network into multiple broadcast domains. Routers operate at Layer 3 and forward packets based on IP addresses. Each interface on a router represents a separate broadcast domain. Routers perform inter-VLAN routing, ensuring that broadcasts from one domain do not reach other domains unless specifically routed, effectively isolating broadcast traffiC)

Option D, a repeater, like a hub, works at Layer 1 to regenerate signals and does not provide any mechanism for separating broadcast domains.In summary, routers are used to create multiple broadcast domains, isolating broadcast traffic and enabling better network segmentation and performance.

Question 16: 

A switchport is configured with the command switchport mode access. What does this mean?

A) The port can carry multiple VLANs
B) The port is a trunk port
C) The port is assigned to a single VLAN
D) The port is administratively down

Answer: C

Explanation: 

An access port is assigned to a single VLAN and does not tag traffiC) Trunk ports are configured to carry multiple VLANs.

In a Cisco switch, the command switchport mode access is used to configure a port to function in a specific way within the VLAN architecture. Understanding the behavior of access and trunk ports is important for designing and troubleshooting VLANs.

Option A, the port can carry multiple VLANs, is incorrect. Ports that carry multiple VLANs are trunk ports, not access ports. Trunk ports use tagging protocols like 802.1Q to differentiate traffic from different VLANs, allowing a single physical link to transport multiple VLANs simultaneously.

Option B, the port is a trunk port, is also incorrect. A trunk port is configured using the command switchport mode trunk, and it tags traffic for multiple VLANs. Access ports do not perform tagging and are limited to a single VLAN.

Option C, the port is assigned to a single VLAN, is correct. When a port is set to access mode, it belongs to one VLAN and carries only untagged traffic for that VLAN. Devices connected to this port communicate only with other devices in the same VLAN unless routed through a Layer 3 device. This configuration is commonly used for end-user devices such as computers, printers, or IP phones that do not need to participate in multiple VLANs.

Option D, the port is administratively down, is unrelated to the switchport mode. A port is administratively down only when it is disabled using the shutdown commanD)

In summary, configuring a switchport with switchport mode access assigns it to a single VLAN, ensuring it carries untagged traffic for that specific VLAN only.

Question 17: 

In IPv6, which address type is used to communicate with all nodes on a local link?

A) Unicast
B) Multicast
C) Anycast
D) Link-local

Answer: D

Explanation: 

IPv6 link-local addresses (FE80::/10) are used for communication between nodes on the same link and are automatically assigned to all IPv6 interfaces.IPv6 uses different types of addresses to facilitate communication between devices, each serving a specific purpose within the network. Understanding these address types is key to configuring and troubleshooting IPv6 networks effectively.

Option A, unicast, refers to an address that identifies a single interface. When a packet is sent to a unicast address, it is delivered only to the specific interface identified by that address. Unicast addresses are not intended for communication with multiple devices simultaneously, so they are not used to reach all nodes on a local link.

Option B, multicast, is used to send packets to a group of devices that have joined a specific multicast group. While multicast addresses can target multiple nodes, they require the receiving devices to subscribe to the group, so they are not automatically used for all nodes on a link.

Option C, anycast, identifies one address that can be assigned to multiple interfaces, usually on different devices. Packets sent to an anycast address are delivered to the nearest interface based on routing distance, rather than all nodes, making it unsuitable for local-link-wide communication.

Option D, link-local, is the correct choice. IPv6 link-local addresses, which use the FE80::/10 prefix, are automatically assigned to every IPv6-enabled interface. They are used for communication between nodes on the same local link, such as for neighbor discovery and routing protocols, ensuring all devices can communicate without requiring global or unique addresses.In summary, link-local addresses in IPv6 enable automatic, local-link-wide communication between all nodes on a segment.

Question 18: 

Which protocol is used to automatically assign IP addresses and configuration information to hosts?

A) DNS
B) DHCP
C) ARP
D) ICMP

Answer: B

Explanation: 

DHCP automatically provides IP addresses, subnet masks, default gateways, and DNS information to hosts on a network, reducing manual configuration errors.

Automatically assigning IP addresses and other network configuration information to hosts is critical for efficient network management, especially in large environments. Doing this manually can lead to errors, misconfigurations, and IP address conflicts.

Option A, DNS (Domain Name System), is not used for assigning IP addresses to hosts. Instead, DNS translates human-readable domain names into IP addresses, allowing users to access websites and network resources by name rather than remembering numerical addresses. DNS provides name resolution but does not handle IP assignment.

Option B, DHCP (Dynamic Host Configuration Protocol), is the correct answer. DHCP allows hosts to automatically obtain IP addresses, subnet masks, default gateway addresses, and DNS server information from a DHCP server. When a host joins the network, it sends a DHCP request, and the server responds with the configuration information, which is leased for a specified perioD) This automation reduces manual configuration errors, prevents IP address conflicts, and simplifies network administration. DHCP is widely used in both enterprise and home networks to streamline device connectivity.

Option C, ARP (Address Resolution Protocol), is used to map IP addresses to MAC addresses on a local network. ARP operates at Layer 2 and Layer 3 to ensure devices can communicate over Ethernet, but it does not assign IP addresses or provide configuration information.

Option D, ICMP (Internet Control Message Protocol), is used for sending error messages and operational information, such as indicating when a host or network is unreachable. ICMP does not handle IP address assignment or network configuration.In summary, DHCP is the protocol that automatically assigns IP addresses and network configuration details to hosts, ensuring efficient and error-free network operations.

Question 19: 

What is the purpose of the Spanning Tree Protocol (STP)?

A) Route traffic between VLANs
B) Prevent Layer 2 loops in a switched network
C) Assign IP addresses dynamically
D) Encrypt switch traffic

Answer: B

Explanation: 

STP prevents Layer 2 switching loops by blocking redundant paths and maintaining a loop-free topology. It dynamically selects a root bridge and calculates port states.

The Spanning Tree Protocol (STP) is a network protocol used in Layer 2 switched networks to ensure a loop-free topology. Loops can occur when there are redundant links between switches, which are often implemented to provide network redundancy and prevent downtime. Without STP, these loops can cause broadcast storms, multiple frame copies, and MAC table instability, severely impacting network performance.

Option A, routing traffic between VLANs, is incorrect. Routing between VLANs is handled by Layer 3 devices, such as routers or Layer 3 switches, using inter-VLAN routing. STP operates at Layer 2 and does not perform routing functions.

Option B, preventing Layer 2 loops in a switched network, is correct. STP works by dynamically identifying redundant paths and placing certain ports into a blocking state to eliminate loops while still maintaining redundancy. It selects a root bridge and calculates the best path for each switch port, ensuring that there is only one active path between any two switches. If the active path fails, STP recalculates and activates a previously blocked path to maintain connectivity.

Option C, assigning IP addresses dynamically, is unrelated to STP. DHCP is the protocol responsible for dynamic IP address assignment.

Option D, encrypting switch traffic, is also incorrect. Encryption of traffic is handled by protocols such as IPsec or SSL/TLS, not STP.In summary, STP’s primary purpose is to prevent Layer 2 loops in a switched network while maintaining redundancy and network stability.

Question 20: 

A network engineer notices that OSPF neighbors are not forming an adjacency on a broadcast network. Which of the following should be verified?

A) OSPF process ID
B) IP addressing and subnet masks
C) OSPF hello and dead intervals
D) All of the above

Answer: D

Explanation: 

OSPF adjacency requires matching hello/dead timers, correct IP addressing within the same subnet, and compatible process IDs on the routers forming the adjacency. Any mismatch prevents neighbor relationships from forming.

When OSPF neighbors fail to form an adjacency on a broadcast network, several factors must be checked to identify and resolve the issue. OSPF requires specific parameters to match between routers in order to establish neighbor relationships and exchange routing information.

Option A, OSPF process ID, should be verifieD) Although OSPF process IDs are locally significant and do not need to match across routers for adjacency to form, using incompatible configurations or multiple processes incorrectly can cause confusion in network management and troubleshooting. Ensuring the correct process is active on the intended interfaces is important for proper neighbor formation.

Option B, IP addressing and subnet masks, is critical. OSPF neighbors must reside on the same subnet to recognize each other as potential neighbors. Incorrect IP addresses or mismatched subnet masks can prevent routers from detecting each other, even if OSPF is correctly configureD) Proper IP configuration ensures that hello packets reach the intended devices.

Option C, OSPF hello and dead intervals, must also match. Routers exchange hello packets to discover and maintain neighbor relationships. If the hello or dead timers are mismatched, routers will fail to recognize each other as neighbors, preventing adjacency formation.

Option D, all of the above, is the correct choice because successful OSPF adjacency requires correct process configuration, proper IP addressing, and matching hello/dead intervals. Any mismatch in these parameters will prevent neighbor relationships from forming.In summary, verifying all these factors ensures proper OSPF adjacency on broadcast networks.