CompTIA Network+ Final Assessment - Exam N10-00

A network engineer oversees a network with 4 subnets of 16 IP addresses each. Each subnet will have the same Classless inter-domain routing (CIDR) range of 192.168.x.0/28, such that the first subnet has an IP range of 192.168.1.0-192.168.1.15, and so forth. If the engineer then needed 62 addresses on each subnet, how many mask bits would be represented in the CIDR notation of each subnet after the engineer has increased the IP range to 62? A. 26 B. 27 C. 32 D. 22

A. 26 A 26-bit mask contains 62 potential IP addresses in its range, from 1 to 62 in the last octet. The subnet mask would look like 255.255.255.192. A 27-bit mask contains 32 potential IP addresses in its range, from 0 to 31 in the last octet. The subnet mask would look like 255.255.255.224. A 32-bit mask contains only a single IP address in its range and represents a single machine on a network. The subnet mask would look like 255.255.255.255. A 22-bit mask contains 1024 potential IP addresses in its range spanning 192.168.0.0 - 192.168.3.255. The subnet mask would look like 255.255.252.0.

A network technician is troubleshooting packet collision issues. The network uses Layer 2 Ethernet switches, and only some ports experience collisions. All of the ports that experience collisions are set at half-duplex; however not all half-duplex ports experience collisions. Recommend the next variable for the technician to check that may be causing collisions in a microsegments switch. A. Are legacy hubs connected to the switch? B. Is DHCP relay enabled? C. Is a packet sniffer being used? D. Is the frame size smaller than the Maximum Transmission Unit (MTU)?

A. Are legacy hubs connected to the switch? Legacy hubs often require half-duplex and can thus enable collisions within the segment branching from the switch port through the legacy hub. If packet collisions are an issue, upgrades should be considered. DHCP Relay is a function that enables IP addresses to be assigned from a server in a separate VLAN. It is related to connection issues but not packet collisions. With the exception of issues caused by power loss if an active tap is installed physically in a network, packet sniffers are not known to affect packet collisions. The frame size isn't usually relevant to packet collision, as small frames are padded and large frames are fragmented. may cause packet loss, but don't cause packet collision per se.

A network technician is manually configuring speed and duplex settings in a managed switch, in order to define specific speeds for specific devices. After testing the manual configuration of a single test device, the technician notes that the LED indicator corresponding to the port the test device is connected to is blinking amber. Recommend a next step for the technician to investigate. A. Check duplex settings B. Wait for the connection to complete C. Ensure cable is plugged into test device and power is on D. The link is connected with no traffic

A. Check duplex settings If a host is set to a fixed configuration and is manually configured to 100 Mbps/full-duplex, the link will fail. A speed mismatch will cause the link to fail, while a duplex mismatch will slow the link down (it will cause high packet loss and late collisions). A blinking amber light indicates a fault has been detected. Waiting won't solve the problem in this case. If there was no power to the test device or the cable was unplugged, there would be no light at all. Indicator light for a normal, healthy ethernet connection with no traffic given to the port is a solid, unblinking green. Anything else indicates some sort of problem.

A team of network engineers is using an interior gateway routing protocol that takes into consideration only the number of hops when calculating routes. Recommend an interior gateway routing protocol that calculates routes using a metric weighted on bandwidth cost combined with delay time, and that only sends updates to neighbors when the topology has changed. A. Enhanced IGRP (EIGRP) B. Routing Information Protocol (RIP) C. Open Shortest Path First (OSPF) D. Border Gateway Protocol (BGP)

A. Enhanced IGRP (EIGRP) EIGRP is an advanced distance-vector or hybrid routing protocol similar to RIP that uses a metric composed of administrator-weighted elements, such as bandwidth and delay. The Routing Information Protocol (RIP) is a distance vector routing protocol. RIP only considers a single metric to select the optimal path to a given destination network, by selecting the one with the lowest hop count (distance). Open Shortest Path First (OSPF) is the most widely adopted link-state protocol. It is a link-state routing protocol, which means that the routers exchange topology information with their nearest neighbors. The Border Gateway Protocol (BGP) is designed to be used between routing domains in a mesh internetwork and is used primarily between ISPs.

A team of network consultants is configuring an Internet of Things (IoT) network. The team is considering network topologies in the context of the IoT devices being used, which are all within 100 meters of one another, are battery-powered, and communicate via the Zigbee protocol. Recommend a network topology that will save power, scale easily to thousands of IoT sensor devices while saving power by cooperating with nearby devices. A. Mesh B. Star C. Bus D. Ring

A. Mesh Mesh networks provide excellent redundancy, because other routes, via intermediary devices, are available between locations if a link failure occurs. In a star topology, each endpoint node is connected to a central forwarding node, such as a hub, switch, or router. The central node mediates communications between the endpoints. A physical bus topology is a shared access topology, meaning that all nodes share the bandwidth of the media. All nodes attach directly to a single cable segment via cable taps. In a physical ring topology, each node is wired to its neighbor in a closed loop. A node receives a transmission from its upstream neighbor and passes it to its downstream neighbor until the transmission reaches its intended destination.

Which Open Systems Interconnection (OSI) model layer is responsible for the transmission of bits of data? A. Physical B. Datalink C. Network D. Transport

A. Physical The physical layer of the OSI model (layer 1) is responsible for the transmission and receipt of the signals that represent bits of data from one node to another node. The data link layer (layer 2) is responsible for transferring data between nodes on the same logical segment. At the Data Link layer, a segment is one where all nodes can send traffic to one another using hardware addresses. The network layer (layer 3) is responsible for moving data (routing) around a network of networks, known as an internetwork or the Internet. The transport layer is known as the end-to-end or host-to-host layer. A function of the transport layer is to identify each type of network application by assigning it a port number.

A network engineer is tracing network routes and counting network hops. The engineers ping packet passes through a total of 3 switches and two routers before reaching its target. Determine how many network hops the packet has taken. The TTL is set to 64. A. 3 B. 2 C. 5 D. 64

B. 2 Two routers count as two hops. Switches do not count as hops. Switches do not count as hops. Switches are layer 2 devices that receive and forward Ethernet frames, using the destination MAC address to determine the correct destination port. Switches are not counted in the hop count. In order to find the right target port, switches use the destination MAC address rather than the transport layer. 64 is the default TTL, or Time To Live, in this case. It is a value that represents how many hops before a connection or packet is dropped, and decrements by one at each hop.

A network cable installer is installing copper cabling in an office for a new network. The installer needs to close a gap of about 150 ft. ending in an RJ-45 termination. What is the lowest possible category of cable needed to maintain 10 Gigabit Ethernet speeds? A. Cat 5e B. Cat 6 C. Cat 8 D. Cat 7

B. Cat 6 Category 6 unshielded twisted pair (UTP) copper cabling can support 10GBASE-T standard speeds at a distance of up to 180 ft. (55 m). Category 5e supports a maximum speed of 1 Gbps at a maximum distance of up to 328 ft (100 m). Category 8 cabling can support speeds up to 40 Gbps up to 100 ft (30 m) and would be overshooting requirements of 10GBASE-T. Category 7 unshielded twisted pair (UTP) copper cabling can support 10GBASE-T standard speeds at a distance of up to 328 ft (100 m). While Cat 7 cables would be ideal for these conditions, it is not the lowest possible category of cable that meets the requirements.

An IT team responsible for a small corporate network is attempting to increase data throughput to a particular machine from 1 Gbps to 2 Gbps. The machine has two network interface cards. Recommend an Ethernet switching feature to fulfill these requirements. A. Port mirroring B. NIC teaming C. Power over Ethernet D. Flow control

B. NIC teaming NIC teaming, also sometimes called port bonding or port aggregation, can be accomplished using the Link Aggregation Control protocol. This can provide redundancy and extra bandwidth when there are multiple clients, as load balancing is performed. A switched-port analyzer can be attached to a network port to mirror the packets being sent. This is often used for traffic analysis, but can also serve as redundancy for failover. Power over Ethernet is a way of supplying electricity from a switch port to an end device using ethernet cabling. PoE will not be useful for maximum doubling bandwidth. Flow control allows a server to instruct the switch to pause traffic temporarily to avoid overwhelming its buffer and preventing frames from being dropped.

A network consultant has just arrived on-premises to address a support ticket regarding several users being unable to log in. Decide which of the following courses of action the consultant should take first. A. Verify full system functionality B. Question users C. Confirm a theory D. Establish a plan of action

B. Question users Questioning users is a part of the first troubleshooting step, identifying the problem. The problem must be identified first, and questioning users regarding details of the problem will help with that. Verification of system functionality is a way of checking whether a solution worked, so it is among the last steps in the troubleshooting methodology. A theory has to be established before it can be confirmed, and theories can't even be formulated without investigation. A plan has to be established before it can be acted upon. A plan can't be formulated without more information.

A company has been advised by a network consultant to have extra lengths of copper twisted-pair cables with 4 pairs of wires as well as 8-position/8-contact connectors. Assess what type of connector will be required. A. RJ-11 B. RJ-45 C. MTRJ D. F-type

B. RJ-45 RJ-45 are used with 4-pair (8-wire) cables. Because each wire has its own contact, they are also known as 8P8C. RJ-11 connectors represent the legacy telephone connectors, utilizing either 2 or 3 pairs of unshielded twisted-pair copper wires. RJ-11 connectors only use 2 contacts, making them 6 position/2 contact or 6P2C MTRJ (Mechanical Transfer Registered Jack) is a small-form-factor duplex fiber-optic connector with a snap-in design that is used in multimode networks. MTRJ connectors are not compatible with copper wire. F-type connectors are used for copper cabling intended for Cable TV, which is attached by a screw and threading mechanism.

How can an IPv4 host send packets to all addresses in a particular subnet? A. Using a unicast packet, addressed to the IP address of the destination host B. Send packets to the closest node in a group C. By sending a packet to the network or subnet's last possible IP address according to the last octet D. Sending packets to subscribed nodes

C. By sending a packet to the network or subnet's last possible IP address according to the last octet A broadcast address is used to send packets to groups of addresses that share a broadcast domain. This groups together devices on the same switch, or on the same VLAN. Unicast packets are addressed to a single receiving IP. They are received by the target only. Anycast addressing routes packets to the closest node in a target group, balancing load, and improving failover. Anycasting provides routing efficiency. Multicast addressing allows a list of addresses in a predefined range to join a multicast group and receive packets targeted at that multiclass group.

A network engineer is creating a network diagram based on a list of media access control (MAC) addresses used in a network. At what layer of the OSI model are all hosts identified by a specific MAC address? A. Physical layer B. Transport layer C. Data-link layer D. Network layer

C. Data-link layer The data link layer (layer 2) is responsible for transferring data between nodes on the same logical segment. At the Data Link layer, a segment is one where all nodes can send traffic to one another using hardware (MAC) addresses. The physical layer of the OSI model (layer 1) is responsible for the transmission and receipt of the signals that represent bits of data from one node to another node. The transport layer is known as the end-to-end or host-to-host layer. A function of the transport layer is to identify each type of network application by assigning port numbers. The network layer (layer 3) is responsible for moving data (routing) around a network of networks, known as an internetwork or the Internet.

What advantage does Collision Detection (CD) bring to the carrier-sense multiple access (CSMA) media access control method? A. Separate collision domains for each port B. 10 Gbps speeds C. Instant termination upon collision D. Full-duplex transmission

C. Instant termination upon collision CSMA Collision Detection utilizes half-duplex transmission to detect when a signal is present on an interface's transmit and receive lines simultaneously. A jamming signal is then used to keep other nodes from transmitting for a period of time. Separate collision/broadcast domains for each port can be done by using VLAN segmentation. It can also be done with a Layer 3 capable switch. Bandwidth can be affected by many factors such as cable category, router capabilities, etc. However, CSMA with Collision Detection does not increase bandwidth directly and is concerned with packet collisions. Because CSMA Collision Detection relies on half-duplex transmission to detect collisions, full-duplex is not used. Modern Ethernet with full-duplex does not require CSMA/CD.

A network consultant is considering potential upgrades for a network that utilizes an edge router that connects to a layer 2 switch, which has ports subinterfaced into multiple VLANs per port. Suggest an upgrade that will increase the efficiency of routing between VLANs by mapping IP addresses to MAC addresses for hardware forwarding. A. Replace the Layer 2 switch with a hub B. Replace the Layer 2 switch with a bridge C. Replace the Layer 2 switch with a Layer 3 switch D. Replace the edge router with a router/firewall combination device

C. Replace the Layer 2 switch with a Layer 3 switch A layer 3 capable switch is optimized for routing between VLANs, and maintains a mapping table of IP addresses to MAC addresses so that when a path is established, it can use low-latency hardware-based forwarding. 100BASE-TX can be implemented with a hub, but most networks started to replace hubs with switches as the connection point for end systems. The contention-based access method used by a hub does not scale to large numbers of end systems within the same collision domain. A bridge is a type of intermediate system that joins physical network segments while minimizing the performance reduction of having more nodes on the same network. Firewall functionality is recommended for edge routers, but will not increase routing efficiency.

A military installation is upgrading its network infrastructure. Which fiber optic connector type developed by AT&T used to be very common for multimode networks in commercial or military installations due to its quick-connecting bayonet, but is no longer considered standard when retrofitting? A. Mechanical Transfer Registered Jack (MTRJ) B. Local Connector (LC) C. Straight Tip (ST) D. Subscriber Connector (SC)

C. Straight Tip (ST) Straight Tip (ST) is an early bayonet-style connector with a twist-and-push locking mechanism. ST was primarily used for multimode networks, however, it is no longer routinely utilized in Ethernet deployments. MTRJ (Mechanical Transfer Registered Jack) is a small-form-factor duplex connector with a snap-in design that is used in multimode networks. The Local Connector (LC) is a small-form-factor connector with a push/pull tabbed design. The LC form factor is commonly used for Gigabit Ethernet and 10/40 GbE. The Subscriber Connector (SC) is a push/pull connector that allows for easy insertion and removal. It may be utilized in either single-mode or multimode mode. It is frequently used in Gigabit Ethernet.

A network engineer investigating connection issues being experienced by users notes that the user clients are able to connect to hosts using an IP address but not using hostnames or URLs. Propose a setting the engineer should check first. A. Check for duplicate IPs B. Failed duplex settings C. Hardware failure D. DNS server settings

D. DNS server settings When a host receives a client request to access a name and it does not have the IP mapping cached, it asks a DNS server configured as a resolver to perform the lookup and return the IP address. If there are two systems with duplicate IPs, a sort of race condition will determine which receives traffic. Autonegotiation of speed and duplex settings being disabled can cause problems. If the speed setting (10, 100, or 1000 Mbps) is mismatched between the host and the switch port, the link will fail. You can test for specific cabling faults and bad ports using cable and loopback testers and certifiers. While hardware failure is rare, cables and appliances do sometimes fail on their own.

How does the TCP/IP protocol suite resolve the machine hardware address of the target IP if the target IP is on a remote network? A. The Internet Group Management Protocol (IGMP) B. From the host ID portion of the IP address C. From the subnet ID portion of the IP address D. Determine the MAC address of the default gateway using ARP cache

D. Determine the MAC address of the default gateway using ARP cache If the destination address is on a remote network, then the local host must use its default gateway to forward the packet. Therefore, it must determine the MAC address of the default gateway using ARP. The Internet Group Management Protocol (IGMP) is typically used to configure multicast group memberships and IP addresses. The Host ID portion of the IP address does identify the host on a network level, however, the hardware MAC address of a remote host cannot be resolved without further action. The subnet ID identifies the particular subnet the target is on, however, the individual machine address and the main network of the subnet itself cannot be discovered without further action.

A team of network engineers are refurbishing copper Ethernet cabling in a FEMA office. The federal government requires that copper twisted pair cabling be terminated according to the T568A standard. To ensure termination is being done according to standard, what color conductor will be wired to the second pin? A. Brown B. Blue C. Orange D. Green

D. Green In T658A and T658B, wires 2 and wires 6 are flipped, so that wire 2 is green in T568A and wire 6 is green in T568B, while wire 6 is orange in T658A and wire 2 is orange according to T658B. Solid brown is the color of wire 8 in both the T568A standard as well as the T568B standard. Solid blue is the color of wire 4 in both the T568A standard as well as the T568B standard. Wire 2 is orange in T658B, and in T658A wire 6 is orange.

A network engineer is testing an application over the IPv6 protocol. Determine how the server can cast packets to an entire local subnet. A. Broadcast packets to a broadcast domain B. Unicast to all Link-Local Multicast Name Resolution hosts C. Anycast to Interface ID D. Multicast to associated private topology

D. Multicast to associated private topology The Multicast Listener Discovery (MLD) protocol allows nodes to join a multicast group and discover whether members of a group are present on a local subnet. Unlike IPv4 where broadcasts are used to flood a broadcast domain with packets, IPv6 does not use packet broadcasting. Link-local addresses span a single subnet (they are not forwarded by routers). Nodes on the same link are referred to as neighbors. Unicast is used to send packets to a single target address. Anycasting is an IP delivery mechanism whereby a packet is addressed to a single host from a group sharing the same address. The Interface ID of an IPv6 address identifies the individual device or port.