200-301 Cisco Certified Network Associate (CCNA) Exam Dumps and Practice Test Questions Set 4 Q61-80

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Question 61: 

Which of the following is a characteristic of a Class C IPv4 address?

A) First octet 1–126
B) First octet 128–191
C) First octet 192–223
D) First octet 224–239

Answer: C

Explanation: 

Class C addresses range from 192–223 in the first octet and use a default subnet mask of 255.255.255.0, commonly used for small networks.

IPv4 addresses are divided into five classes—A, B, C, D, and E—based on the range of values in their first octet, which helps determine the network size and purpose of the address. Each class has unique characteristics, including the number of networks, hosts per network, and default subnet masks. Understanding these ranges is essential for network design and management.

Class A addresses have a first octet ranging from 1 to 126. These addresses are designed for very large networks, as they allow for a huge number of hosts per network. Their default subnet mask is 255.0.0.0, meaning the first octet identifies the network and the remaining three octets identify hosts within that network. Class A addresses are typically assigned to major organizations with extensive network requirements.

Class B addresses occupy the first octet range of 128 to 191. They are used for medium to large-sized networks. The default subnet mask is 255.255.0.0, meaning the first two octets represent the network portion and the remaining two octets identify hosts. Class B strikes a balance between the number of networks and the number of hosts per network, making it suitable for universities, large businesses, and ISPs.

Class C addresses, with the first octet ranging from 192 to 223, are designed for small networks. Their default subnet mask is 255.255.255.0, which allocates the first three octets to the network portion and the last octet to host addresses. This allows for up to 254 usable host addresses per network, making it ideal for small organizations, offices, or local area networks. Class C addresses are the most commonly used for standard network setups.

Class D addresses range from 224 to 239 in the first octet and are reserved for multicast purposes. These addresses are not assigned to individual hosts but are used to deliver data to multiple destinations simultaneously. Finally, Class E addresses, ranging from 240 to 255, are reserved for experimental purposes and are not used in standard networking.

In summary, a Class C IPv4 address is characterized by a first octet between 192 and 223, a default subnet mask of 255.255.255.0, and suitability for small networks.

Question 62: 

A network administrator wants to allow hosts on multiple VLANs to communicate. Which device is required?

A) Hub
B) Switch
C) Router or Layer 3 switch
D) Access point

Answer: C

Explanation: 

Inter-VLAN communication requires a Layer 3 device to route traffic between VLANs, either through a router-on-a-stick or a Layer 3 switch.

In a network environment where multiple VLANs (Virtual Local Area Networks) are implemented, each VLAN functions as a separate broadcast domain. This segmentation improves network performance and security by isolating traffic within each VLAN. However, devices in different VLANs cannot communicate directly because they are on different network segments. To enable communication between VLANs, a device capable of routing traffic at Layer 3 of the OSI model is requireD)

A hub is a simple network device that operates at Layer 1. It merely repeats incoming signals to all ports, allowing devices to share the same collision domain. Hubs cannot distinguish between VLANs or route traffic between them, making them unsuitable for inter-VLAN communication.

A switch operates primarily at Layer 2, using MAC addresses to forward frames within a single VLAN. While switches are excellent for segmenting networks into multiple VLANs, a standard Layer 2 switch cannot route traffic between VLANs on its own. Without additional configuration or the involvement of a Layer 3 device, hosts on separate VLANs remain isolateD)

A router or Layer 3 switch is specifically designed to handle inter-VLAN communication. Routers operate at Layer 3 and use IP addresses to make forwarding decisions, allowing them to route traffic between different VLANs. This can be achieved using a router-on-a-stick configuration, where a single router interface is logically divided into subinterfaces, each associated with a different VLAN, or by using a Layer 3 switch that can perform routing internally without the need for an external router. These devices examine IP addresses, determine the best path for traffic, and forward packets between VLANs, enabling full communication across different network segments.An access point is used to provide wireless connectivity to devices and typically operates at Layer 2. It allows wireless clients to join a VLAN but does not perform routing between VLANs.Therefore, to allow hosts on multiple VLANs to communicate, a router or Layer 3 switch is required, as it can route traffic between VLANs and provide connectivity across separate broadcast domains, ensuring efficient and secure network communication.

Question 63: 

Which command on a Cisco switch displays interface status, VLAN assignment, duplex, and speed?

A) show vlan brief
B) show interfaces status
C) show running-config
D) show mac-address-table

Answer: B

Explanation: 

show interfaces status provides details about interface operational status, VLAN membership, speed, and duplex, useful for troubleshooting.

On a Cisco switch, it is often necessary for network administrators to verify the status and configuration of switch interfaces to ensure proper operation and troubleshoot network issues. The command that provides a comprehensive view of interface details, including operational status, VLAN assignment, duplex, and speed, is show interfaces status. This command displays each interface’s state, whether it is administratively up or down, the VLAN it belongs to, the operational speed, and the duplex mode, which can be half or full. This information is particularly useful when diagnosing connectivity problems, verifying VLAN assignments, or checking for mismatched speed and duplex settings that can cause network performance issues.

The show vlan brief command provides a summary of VLANs configured on the switch, including VLAN IDs, names, and ports assigned to each VLAN. While this is useful for quickly checking VLAN configuration and membership, it does not display detailed interface information such as operational status, speed, or duplex.

The show running-config command displays the current configuration running on the switch, including interface configurations, VLANs, trunking, and other settings. While it shows the intended configuration, it does not reflect real-time operational data like the actual interface status or negotiated speed and duplex. Therefore, it is more useful for configuration review than for immediate troubleshooting of interface issues.

The show mac-address-table command displays the MAC addresses that the switch has learned on its interfaces and the corresponding VLANs. This is helpful for identifying which devices are connected to which ports but does not provide information about interface status, speed, or duplex.

In summary, the show interfaces status command is the most appropriate for quickly obtaining real-time information about interface operational status, VLAN membership, speed, and duplex. It allows administrators to verify both configuration and operational conditions, making it an essential command for monitoring and troubleshooting Cisco switches.

Question 64: 

Which protocol is connectionless and does not guarantee delivery?

A) TCP
B) UDP
C) FTP
D) SSH

Answer: B

Explanation: 

UDP is connectionless and does not provide acknowledgments, sequencing, or retransmission, making it faster but less reliable than TCP.

In computer networking, understanding the difference between connection-oriented and connectionless protocols is crucial for selecting the appropriate protocol for different applications. Among the options listed, UDP, or User Datagram Protocol, is a connectionless protocol that does not guarantee delivery of datA) This means that when data packets are sent using UDP, the protocol does not establish a dedicated end-to-end connection before transmission. It also does not provide mechanisms for acknowledgment, sequencing, or retransmission in case packets are lost or arrive out of order. Because of this simplicity, UDP has very low overhead and offers faster communication compared to connection-oriented protocols like TCP.

TCP, or Transmission Control Protocol, is a connection-oriented protocol. Unlike UDP, TCP establishes a reliable connection between the sender and receiver before data is transmitteD) It guarantees that all packets will be delivered in the correct order by using acknowledgments, sequence numbers, and retransmissions if necessary. TCP is suitable for applications where reliability is critical, such as web browsing, email, and file transfers.

FTP, or File Transfer Protocol, is an application-layer protocol that relies on TCP to transfer files between devices. It inherits TCP’s reliability features, ensuring that all data arrives intact and in order. FTP cannot function without a reliable transport layer like TCP, making it fundamentally different from connectionless protocols like UDP.

SSH, or Secure Shell, is another application-layer protocol that also depends on TCP. It provides secure, encrypted remote access to devices. Like FTP, SSH relies on TCP’s connection-oriented nature to ensure reliable and ordered delivery of data, which is essential for secure command execution and session integrity.

Question 65: 

A router is configured with the command router eigrp 100. What does 100 represent?

A) Autonomous system number
B) Interface number
C) Metric cost
D) Subnet mask

Answer: A

Explanation: 

In EIGRP, the number following router eigrp specifies the autonomous system (AS) to which the router belongs. Routers must share the same AS to exchange routes.

Enhanced Interior Gateway Routing Protocol (EIGRP) is an advanced distance-vector routing protocol used to exchange routing information within a network. When configuring EIGRP on a router, the command router eigrp 100 is useD) In this command, the number 100 represents the autonomous system (AS) number. An autonomous system is a collection of routers under a common administrative domain that share routing information among themselves. For routers to successfully exchange EIGRP routes, they must belong to the same autonomous system. The AS number acts as an identifier, ensuring that routers do not inadvertently share routes with routers outside their administrative domain.

Option B, interface number, is incorrect because the interface number identifies specific router ports or connections, not the routing domain. Interface configuration is performed separately, typically under each interface using commands like ip address and network statements to include the interface in EIGRP.

Option C, metric cost, is also incorrect. While EIGRP uses a composite metric based on bandwidth, delay, load, and reliability to determine the best path, the number 100 in the router eigrp 100 command does not specify the metriC) Metric calculations are performed automatically by the protocol unless manually adjusted with metric weights.

Option D, subnet mask, is not correct either. The subnet mask defines the size of the network portion of an IP address but has no role in specifying the EIGRP autonomous system. Subnet masks are applied to interfaces or network statements to determine which IP addresses participate in the routing process.

In summary, the number following the router eigrp command identifies the autonomous system. All routers within the same AS number exchange routes and maintain a consistent view of the network, enabling efficient and controlled routing. Using different AS numbers isolates routing domains, preventing unintended sharing of routing information. This makes the autonomous system number a critical element in EIGRP configuration and operation.

Question 66: 

A network engineer notices that hosts cannot ping each other on the same VLAN. Which configuration is most likely missing?

A) IP address on hosts
B) Default gateway
C) VLAN configuration on switch
D) OSPF routing

Answer: C

Explanation: 

If hosts are on the same VLAN but cannot communicate, the VLAN might not be configured or assigned properly on the switch. Hosts in the same VLAN must be in the same broadcast domain.

In a network, VLANs (Virtual Local Area Networks) are used to segment a switch into multiple broadcast domains, improving network performance and security. If hosts on the same VLAN cannot communicate with each other, one of the most likely issues is that the VLAN is not configured correctly on the switch or the switch ports are not assigned to the correct VLAN. Each VLAN creates a separate broadcast domain, and for hosts to communicate within the same VLAN, the switch must recognize the VLAN and have the ports assigned to it. Without proper VLAN configuration, traffic from one host will not reach another host, even if they are physically connected to the same switch.

Option A, IP address on hosts, is important because hosts need an IP address to communicate at Layer 3. However, even without an IP address, hosts should still be able to communicate at Layer 2 using MAC addresses if the VLAN is correctly configureD) Therefore, missing IP addresses would affect higher-level communication like pinging across subnets, but intra-VLAN connectivity issues are more likely due to VLAN misconfiguration.

Option B, default gateway, is required for hosts to communicate outside their local subnet or VLAN. If hosts are on the same VLAN, they do not require a default gateway to communicate with each other. Missing a default gateway would not prevent pinging within the same VLAN.

Option D, OSPF routing, is a dynamic routing protocol used for communication between different networks or VLANs. OSPF is irrelevant to communication within the same VLAN, as hosts in the same VLAN communicate at Layer 2.

In conclusion, the most likely missing configuration when hosts on the same VLAN cannot ping each other is the VLAN configuration on the switch. Ensuring that the VLAN exists on the switch and that all relevant ports are correctly assigned to that VLAN is essential. This configuration places hosts in the same broadcast domain, enabling proper Layer 2 communication and allowing them to ping each other successfully.

Question 67: 

Which protocol is used to dynamically update IP-to-MAC address mappings on a network?

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

Answer: B

Explanation: 

ARP dynamically resolves IPv4 addresses to MAC addresses, allowing devices to communicate on a local network segment.

In a local area network, devices communicate using both IP addresses and MAC addresses. While IP addresses operate at Layer 3 and identify devices logically on a network, MAC addresses operate at Layer 2 and are used to deliver frames within the same local network segment. To allow communication between devices on a local network, a protocol is required to dynamically resolve an IP address into its corresponding MAC address. Address Resolution Protocol (ARP) performs this exact function.

When a device wants to send data to another device on the same network, it first checks its ARP cache to see if it already knows the MAC address corresponding to the destination IP. If not, it sends an ARP request as a broadcast on the local network. The device with the matching IP address responds with its MAC address, which is then stored in the ARP cache for future use. This dynamic process allows devices to communicate efficiently without manually configuring IP-to-MAC mappings.

Option A, DNS, or Domain Name System, translates human-readable domain names into IP addresses. While DNS helps devices locate each other on a network or the internet, it does not resolve IP addresses into MAC addresses.

Option C, DHCP, or Dynamic Host Configuration Protocol, dynamically assigns IP addresses and other network configuration parameters to devices on a network. DHCP ensures that devices receive valid IP addresses, subnet masks, and default gateways, but it does not provide MAC address resolution for communication within the local network.

Option D, ICMP, or Internet Control Message Protocol, is used for diagnostic and control purposes, such as sending echo requests and replies for ping operations. ICMP does not handle address resolution or mapping between IP and MAC addresses.

In conclusion, ARP is the protocol responsible for dynamically updating IP-to-MAC address mappings on a local network. It enables devices to determine the hardware address associated with an IP, ensuring successful delivery of data frames within a broadcast domain. Without ARP, communication between devices on the same network segment would not be possible.

Question 68: 

Which Cisco IOS command verifies the status of HSRP on a router?

A) show ip route
B) show standby
C) show running-config
D) show interfaces

Answer: B

Explanation: 

show standby displays HSRP configuration, including active and standby routers, priority, timers, and virtual IP addresses.

Hot Standby Router Protocol (HSRP) is a Cisco proprietary protocol used to provide network redundancy for IP networks. HSRP allows two or more routers to work together to present the appearance of a single virtual router to hosts on a local network. This ensures continuous network availability in case the active router fails. To verify the status and operation of HSRP on a router, the Cisco IOS command show standby is useD) This command provides detailed information about HSRP groups, including the active and standby routers, priority values, HSRP timers, and the virtual IP and MAC addresses configured for the group. It allows network administrators to monitor the redundancy setup and troubleshoot any issues with HSRP.

Option A, show ip route, displays the routing table of the router. It lists all known routes, including connected, static, and dynamically learned routes, but it does not provide information about HSRP groups or their status. While this command is useful for verifying general routing information, it cannot verify HSRP operation or determine which router is currently active.

Option C, show running-config, displays the router’s current configuration stored in RAM. While this command shows the configured HSRP settings, such as interface configurations and HSRP group numbers, it does not provide real-time operational status, timers, or indicate which router is currently active. Therefore, it is not sufficient to verify the actual status of HSRP.

Option D, show interfaces, provides details about the physical and logical status of router interfaces, including bandwidth, errors, and IP addresses. Although it can help verify that interfaces are operational, it does not provide information about HSRP group membership or the virtual IP addresses associated with HSRP.

In conclusion, the show standby command is the appropriate choice to verify the status of HSRP on a Cisco router. It allows administrators to view real-time HSRP group operation, confirm which router is active, and ensure that redundancy mechanisms are functioning correctly, ensuring high network availability.

Question 69: 

Which IPv6 address is used for a single device?

A) Unicast
B) Multicast
C) Anycast
D) Broadcast

Answer: A

Explanation: 

Unicast addresses identify a single interface, allowing one-to-one communication. IPv6 does not use broadcast addresses.

IPv6, the most recent version of the Internet Protocol, uses different types of addresses to facilitate communication between devices. One of the primary types of IPv6 addresses is the unicast address. A unicast address uniquely identifies a single interface on a network, allowing one-to-one communication between devices. When a packet is sent to a unicast address, it is delivered directly to the interface identified by that address. Unicast communication is essential for tasks such as host-to-host data transfer, management access, and client-server communication. Examples of IPv6 unicast addresses include global unicast addresses, link-local addresses, and unique local addresses.

Multicast addresses, on the other hand, are designed for one-to-many communication. When a packet is sent to a multicast address, it is delivered to all interfaces that are subscribed to that specific multicast group. Multicast is commonly used for applications such as streaming video, group communication, or routing protocols that need to send updates to multiple devices simultaneously. Unlike unicast, multicast does not target a single device but a specific group of devices.

Anycast addresses are used to identify a group of interfaces, usually on different devices, where the packet is delivered to the nearest interface based on routing distance. Anycast is often used for services like DNS or content delivery networks, where requests should be handled by the closest server to improve response times.

IPv6 does not support traditional broadcast addresses, unlike IPv4. In IPv4, broadcast addresses allow one-to-all communication within a subnet. IPv6 replaces the broadcast concept with multicast, making the network more efficient by limiting unnecessary traffiC)

Question 70: 

Which command enables a switch port to be a trunk port carrying multiple VLANs?

A) switchport mode access
B) switchport mode trunk
C) switchport port-security
D) switchport nonegotiate

Answer: B

Explanation: 

switchport mode trunk configures the port to carry multiple VLANs, tagging frames with 802.1Q VLAN identifiers.

In a network using VLANs, switch ports must be configured appropriately to handle traffic for one or more VLANs. By default, switch ports are access ports, meaning they carry traffic for a single VLAN. To enable a port to carry traffic for multiple VLANs, it must be configured as a trunk port. The Cisco IOS command switchport mode trunk is used to configure a switch port as a trunk. When a port is in trunk mode, it can carry traffic for multiple VLANs simultaneously, and each frame is tagged with a VLAN identifier using the IEEE 802.1Q standarD) This allows devices on different switches to maintain VLAN segregation while sharing the same physical link, enabling communication across VLANs through the trunk link.

Option A, switchport mode access, configures a port as an access port. Access ports are assigned to a single VLAN and do not tag frames. They are used for end devices such as computers, printers, or IP phones. This configuration does not allow multiple VLANs to traverse the port, making it unsuitable for inter-switch connections or carrying multiple VLANs.

Option C, switchport port-security, is a security feature that limits the number of MAC addresses that can be learned on a port and can take action if unauthorized devices attempt to connect. While important for securing a network, it does not change the port’s ability to carry multiple VLANs. Port security is typically applied to access ports, not trunk ports.

Option D, switchport nonegotiate, disables Dynamic Trunking Protocol (DTP) negotiation on the port. This command prevents the switch from negotiating trunking automatically with the connected device. It is used in certain scenarios to ensure the port remains a trunk without negotiation, but it does not, by itself, enable trunking.

In summary, the command switchport mode trunk is used to configure a switch port to carry multiple VLANs. It allows frames from different VLANs to traverse a single physical link by tagging them with 802.1Q identifiers, enabling VLAN connectivity across switches while maintaining VLAN separation.

Question 71: 

Which protocol allows routers to share routing information in a hierarchical topology using areas?

A) RIP
B) OSPF
C) EIGRP
D) BGP

Answer: B

Explanation: 

OSPF supports hierarchical network design using areas, reducing routing table size and limiting LSAs for scalability.

Open Shortest Path First (OSPF) is a widely used link-state routing protocol that allows routers to dynamically share routing information. One of OSPF’s key features is its support for a hierarchical network design using areas. In a hierarchical topology, the network is divided into multiple areas with a central backbone area known as Area 0. This design reduces the size of routing tables and limits the scope of Link-State Advertisements (LSAs), which enhances scalability and improves overall network performance. Routers within the same area maintain detailed information about the area’s topology, while routers connecting different areas exchange summarized routes, reducing processing and memory requirements.

Option A, RIP (Routing Information Protocol), is a distance-vector routing protocol. RIP shares routing information based on hop count and does not support a hierarchical design with areas. Its simplicity limits scalability, and it cannot efficiently handle large or complex networks.

Option C, EIGRP (Enhanced Interior Gateway Routing Protocol), is an advanced distance-vector or hybrid routing protocol. While EIGRP supports summarization and rapid convergence, it does not use a formal hierarchical area structure like OSPF. EIGRP organizes networks using autonomous systems but lacks the area concept to manage LSAs and optimize large-scale deployments.

Option D, BGP (Border Gateway Protocol), is an exterior gateway protocol primarily used to exchange routing information between different autonomous systems on the Internet. BGP does not operate with OSPF-style areas or hierarchical link-state routing within an enterprise network. Its focus is policy-based routing and path selection across multiple ASes rather than internal network topology management.

In conclusion, OSPF is the protocol that allows routers to share routing information in a hierarchical topology using areas. By dividing the network into multiple areas, OSPF reduces routing table complexity, limits LSA flooding, and supports scalable and efficient network design. This makes it the preferred choice for medium to large enterprise networks requiring a structured and manageable routing approach.

Question 72: 

Which command displays the current VLAN configuration on a Cisco switch?

A) show interfaces
B) show vlan brief
C) show running-config
D) show ip route
Answer: B

Explanation: 

show vlan brief lists all VLANs, their status (active or suspended), and assigned ports, helping verify VLAN configuration.

On a Cisco switch, it is essential for network administrators to verify the VLAN configuration to ensure proper segmentation and connectivity of network devices. The command show vlan brief is specifically designed to display the current VLAN configuration on a switch. This command provides a concise summary of all VLANs configured on the device, their operational status, and the ports assigned to each VLAN. The output typically shows VLAN IDs, VLAN names, status (active or suspended), and the list of switch ports associated with each VLAN. Using this command, administrators can quickly confirm that VLANs are created correctly and that devices are connected to the intended VLANs.

Option A, show interfaces, provides information about the physical and logical status of each interface on the switch, including whether the interface is administratively up or down, link status, speed, and duplex settings. While useful for verifying interface operation, this command does not provide a summary of VLANs or their port assignments, so it cannot fully confirm VLAN configuration.

Option C, show running-config, displays the current configuration of the switch stored in RAM. It includes interface configurations, VLAN assignments, trunk settings, and other device parameters. Although this command contains the VLAN information in detail, the output can be lengthy and complex, making it harder to quickly verify VLAN status and port assignments compared to show vlan brief.

Option D, show ip route, shows the routing table of the device, listing all known IP routes, including directly connected, static, and dynamically learned routes. This command is related to Layer 3 routing and does not provide information about VLANs or their associated switch ports.

Question 73: 

Which type of routing protocol uses metrics like bandwidth, delay, and reliability?

A) RIP
B) EIGRP
C) OSPF
D) BGP

Answer: B

Explanation: 

EIGRP uses a composite metric based on bandwidth, delay, load, and reliability to calculate the best path. RIP only uses hop count.

Enhanced Interior Gateway Routing Protocol (EIGRP) is an advanced Cisco proprietary routing protocol that uses a composite metric to determine the best path for data transmission. Unlike simpler routing protocols, EIGRP evaluates multiple factors when calculating its metrics, including bandwidth, delay, load, and reliability. This allows it to select the most efficient and stable path to a destination, rather than simply the path with the fewest hops. By considering these metrics, EIGRP can provide faster convergence, more accurate route selection, and improved network performance, making it suitable for medium to large enterprise networks.

Option A, RIP (Routing Information Protocol), is a distance-vector routing protocol that uses only hop count as its metriC) RIP is simpler and easier to configure but less sophisticated, as it does not account for factors such as bandwidth or delay. Its reliance on hop count alone can result in suboptimal routing, particularly in large or complex networks.

Option C, OSPF (Open Shortest Path First), is a link-state routing protocol that calculates the shortest path based on cost. The OSPF cost is typically derived from the interface bandwidth. While OSPF can indirectly factor in speed, it does not use a composite metric like EIGRP that combines multiple parameters such as delay, reliability, and loaD)

Option D, BGP (Border Gateway Protocol), is an exterior gateway protocol used to exchange routing information between autonomous systems on the internet. BGP primarily uses path attributes such as AS path, next-hop, and policy-based routing decisions rather than network performance metrics like bandwidth or delay.

In summary, EIGRP is the routing protocol that uses a composite metric including bandwidth, delay, load, and reliability to determine the optimal path. This approach allows it to make more informed routing decisions compared to RIP, OSPF, or BGP, which either use simpler metrics or rely on policy-based path selection. EIGRP’s metric calculation ensures efficient, reliable, and scalable routing within enterprise networks.

Question 74: 

Which command verifies the IP address and subnet mask assigned to a router interface?

A) show ip route
B) show ip interface brief
C) show running-config
D) ping

Answer: B

Explanation: 

show ip interface brief provides a concise summary of each interface, including IP address, status, and protocol state.

On a Cisco router, it is essential to verify the IP address and subnet mask assigned to each interface to ensure proper connectivity and network configuration. The command show ip interface brief is the most effective way to achieve this. This command provides a concise summary of all router interfaces, listing their IP addresses, interface status (administratively up or down), and protocol status (up or down). By using this command, network administrators can quickly confirm whether interfaces are configured correctly and are operational, making it an essential tool for troubleshooting and verifying interface settings.

Option A, show ip route, displays the router’s routing table, which includes all known routes, directly connected networks, and routes learned via dynamic routing protocols. While this command shows which networks the router can reach, it does not provide a direct summary of interface IP addresses or subnet masks. It is more useful for verifying reachability and understanding the overall routing behavior of the device rather than confirming interface configurations.

Option C, show running-config, displays the router’s current configuration stored in RAM. This includes all interface configurations, IP addresses, subnet masks, routing protocols, and other device settings. Although show running-config contains the IP address information, the output can be lengthy and detailed, making it less efficient for quickly verifying the operational status of interfaces compared to show ip interface brief.

Option D, ping, is a diagnostic tool used to test connectivity between devices on a network. While it can confirm whether a host or interface is reachable, it does not display the IP address or subnet mask of the router’s interfaces.

In summary, show ip interface brief is the optimal command to verify the IP address and subnet mask of a router’s interfaces. It provides a quick, clear view of all interfaces, their assigned IP addresses, and operational status, allowing administrators to ensure proper configuration and troubleshoot connectivity issues efficiently.

Question 75: 

Which type of ACL filters traffic based solely on the source IP address?

A) Standard ACL
B) Extended ACL
C) Reflexive ACL
D) Named ACL

Answer: A

Explanation: 

Standard ACLs filter traffic only by source IP, whereas extended ACLs can filter by source, destination, protocol, and ports.

Access Control Lists (ACLs) are used in networking to filter and control traffic passing through a router or switch. ACLs help improve network security by allowing or denying packets based on defined criteriA) There are several types of ACLs, each designed for different levels of traffic filtering. Standard ACLs are the simplest type of ACL. They filter traffic solely based on the source IP address of the packets. By using a standard ACL, a network administrator can permit or deny traffic coming from specific source addresses, regardless of the destination, protocol, or port numbers. This type of ACL is effective for basic access control but provides limited granularity.

Extended ACLs, in contrast, allow more precise control over traffiC) They can filter packets based on multiple criteria, including source and destination IP addresses, Layer 4 protocol types (such as TCP or UDP), and specific port numbers. This makes extended ACLs suitable for environments where more detailed traffic management is required, such as controlling web access or allowing certain applications while blocking others.

Reflexive ACLs are dynamic and allow temporary traffic flows based on sessions initiated from inside the network. They are often used for security purposes to track outgoing connections and permit return traffic dynamically. This type of ACL is more advanced and provides stateful filtering capabilities.

Named ACLs are simply ACLs that are assigned descriptive names instead of numeric identifiers. They can be either standard or extended, but the primary difference is that the name makes them easier to manage and understand in complex network configurations.

In summary, standard ACLs filter traffic solely based on the source IP address, making them the simplest and most basic type of ACL. Extended ACLs provide filtering based on multiple criteria, reflexive ACLs support dynamic session-based filtering, and named ACLs offer easier identification and management. When the goal is simply to control traffic originating from specific sources without concern for destination or protocol, standard ACLs are the most appropriate choice.

Question 76: 

Which protocol resolves hostnames to IP addresses?

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

Answer: C

Explanation: 

DNS (Domain Name System) translates domain names into IP addresses, allowing users to access resources using human-readable names.

In networking, devices communicate using IP addresses, which are numerical identifiers for each host on a network. Remembering these numerical addresses can be difficult for users, so a system is needed to translate human-readable domain names, like www.example.com, into IP addresses. The Domain Name System (DNS) fulfills this role. DNS is a hierarchical and distributed naming system that maps hostnames to IP addresses, allowing users to access websites and other network resources using familiar names instead of numeric addresses. When a user enters a domain name in a browser, a DNS query is sent to a DNS server, which responds with the corresponding IP address.

Option A, DHCP (Dynamic Host Configuration Protocol), is a protocol used to assign IP addresses and other network configuration information to hosts automatically. While DHCP ensures that devices can join a network with proper IP settings, it does not resolve hostnames to IP addresses. Its main role is in IP address management rather than name resolution.

Option B, ARP (Address Resolution Protocol), is used within a local network to map an IP address to a physical MAC address. ARP operates at Layer 2 of the OSI model and is essential for local communication between devices on the same subnet. However, it does not translate human-readable hostnames into IP addresses, so it does not serve the same purpose as DNS.

Option D, ICMP (Internet Control Message Protocol), is a network layer protocol used primarily for diagnostic and control purposes, such as pinging a host to test connectivity. ICMP does not provide any mapping of hostnames to IP addresses.

Question 77: 

Which IPv6 feature allows multiple devices to share a single address for routing purposes?

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

Answer: A

Explanation: 

Anycast allows multiple devices to share the same IPv6 address. Packets are routed to the nearest device based on routing metrics.

Question 78: 

Which command displays the routing table of a Cisco router?

A) show ip interface brief
B) show ip route
C) show running-config
D) show vlan brief

Answer: B

Explanation: 

show ip route displays all routes in the router’s routing table, including directly connected, static, and dynamic routes.

In networking, the routing table of a router contains critical information about the paths that data packets take to reach their destinations. On a Cisco router, the command show ip route is used to display the routing table. This command provides a comprehensive view of all known routes, including directly connected networks, static routes manually configured by the administrator, and dynamically learned routes through routing protocols such as OSPF, EIGRP, or RIP. The output includes the destination network, the next-hop IP address, the exit interface, and the routing protocol used to learn the route. By examining the routing table, network administrators can verify connectivity, troubleshoot routing issues, and ensure that the router has correct paths to all necessary networks.

Option A, show ip interface brief, displays a concise summary of the router’s interfaces, showing IP addresses, operational status, and protocol status. While it is useful for verifying interface configurations and checking whether interfaces are up or down, it does not provide information about the routing paths or how the router forwards traffic to remote networks.

Option C, show running-config, displays the current configuration running on the router, including interface settings, routing protocol configurations, access control lists, and other parameters. While it includes the configuration of static and dynamic routing protocols, it does not reflect the actual routing table with the real-time learned or active routes. Therefore, it is useful for configuration review but not for immediate verification of the routing paths.

Option D, show vlan brief, is specific to switches and lists VLANs, their status, and the ports assigned to each VLAN. This command is unrelated to routing and does not provide any information about IP routes or network reachability.

Question 79: 

Which mechanism allows multiple physical links to act as one logical link between switches?

A) STP
B) EtherChannel
C) VLAN trunking
D) HSRP

Answer: B

Explanation: 

EtherChannel combines multiple links into a single logical link, providing higher bandwidth, redundancy, and load balancing.

Question 80: 

Which command verifies which routes are learned via OSPF on a router?

A) show ip ospf neighbor
B) show ip route ospf
C) show running-config
D) show ip interface brief

Answer: B

Explanation: 

show ip route ospf displays all OSPF-learned routes in the routing table, including prefixes, next hops, and interfaces used to reach destinations.

Open Shortest Path First (OSPF) is a widely used link-state routing protocol that enables routers to exchange routing information within an autonomous system. When troubleshooting or verifying OSPF operation on a router, it is often necessary to identify which routes in the routing table were learned via OSPF. The Cisco IOS command show ip route ospf accomplishes this task. This command filters the routing table to display only those routes that OSPF has contributeD) The output includes destination network prefixes, next-hop IP addresses, and the outgoing interfaces used to reach those destinations. By using this command, network administrators can confirm that OSPF is functioning correctly, verify route propagation, and troubleshoot any missing or unexpected routes.

Option A, show ip ospf neighbor, displays information about OSPF neighbors, including their state, IP address, and interface used for adjacency. This command is essential for verifying OSPF neighbor relationships and understanding how routers communicate within the OSPF areA) While it confirms that OSPF adjacencies are established, it does not display which routes have been learned through OSPF, so it cannot directly verify OSPF routing entries.

Option C, show running-config, displays the current configuration of the router, including OSPF process settings, network statements, and interface configurations. This command provides insight into how OSPF is configured but does not indicate which routes have been successfully learned or installed in the routing table.

Option D, show ip interface brief, provides a summary of all router interfaces, their IP addresses, and operational status. This is useful for verifying interface connectivity but offers no information about OSPF routing or learned routes.

In summary, show ip route ospf is the correct command to verify which routes are learned via OSPF. It provides a clear view of OSPF-contributed routes, including next hops and interfaces, allowing administrators to ensure proper OSPF operation, route propagation, and network reachability within the OSPF-enabled environment.