Domain 1 Networking Concepts

Which of the following routing protocols can you use on a TCP/IP internetwork with segments running at different speeds, making hop counts an inaccurate measure of route efficiency? (Choose all correct answers.) A. Enhanced Interior Gateway Routing Protocol (EIGRP) B. Routing Information Protocol (RIP) C. Open Shortest Path First (OSPF) D. Border Gateway Protocol (BGP)

A and C. OSPF is a link state routing protocol, which means that it does not rely solely on hop counts to measure the relative efficiency of a route. EIGRP is a hybrid protocol that can use link state routing. RIP is a distance vector routing protocol, meaning that it uses hop counts to measure route efficiency. BGP is an exterior gateway protocol that exchanges routing information among autonomous systems using path vectors or distance vectors.

What is the maximum number of routes that can be included in a single RIP broadcast packet? A. 20 B. 25 C. 32 D. Unlimited

B. A single RIP broadcast packet can include up to 25 routes. If there are more than 25 routes in the computer's routing table, then RIP must generate additional packets.

Specify the layer of the Open Systems Interconnection (OSI) model at which the Internet Protocol (IP) operates and whether it is connectionoriented or connectionless. A. Network; connection-oriented B. Network; connectionless C. Transport; connection-oriented D. Transport; connectionless

B. IP is a connectionless protocol that operates at the network layer of the OSI model. There are no connection-oriented protocols at this layer. The protocols at the transport layer include Transmission Control Protocol (TCP), which is connection-oriented, and User Datagram Protocol (UDP), which is connectionless.

At which layer of the Open Systems Interconnection (OSI) model is there a protocol that adds both a header and footer to the information that is passed down from an upper layer, thus creating a frame? A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

B. The only layer with a protocol (such as Ethernet) that adds both a header and a footer is the data link layer. The process of adding the headers and footers is known as data encapsulation. All other protocol layers that encapsulate data add just a header.

Which of the following protocols provides connectionless delivery service at the transport layer of the Open Systems Interconnection (OSI) model? A. TCP B. HTTP C. UDP D. ARP

C. The User Datagram Protocol (UDP) provides connectionless service at the transport layer. TCP provides connection-oriented service at the transport layer. HTTP is an application layer protocol, and ARP is a data link layer protocol.

Which of the following are techniques used in traffic shaping to prevent networks from being overwhelmed by data transmissions? (Choose all correct answers.) A. Bandwidth throttling B. Rate limiting C. Broadcast storming D. Network address translation

A and B. Bandwidth throttling is a traffic shaping technique that prevents specified data streams from transmitting too many packets. Rate limiting is a traffic shaping technique that controls the transmission rate of sending systems. A broadcast storm is a type of network switching loop. Network address translation is a method by which private networks can share registered IP addresses. Neither of these last two is a traffic shaping technique.

Which of the following protocols operate at the application layer of the Open Systems Interconnection (OSI) model? (Choose all correct answers.) A. HTTP B. SNMP C. ICMP D. IGMP E. UDP

A and B. Hypertext Transfer Protocol (HTTP) and Simple Network Management Protocol (SNMP) operate at the application layer. Internet Control Message Protocol (ICMP) and Internet Group Management Protocol (IGMP) both operate at the network layer. User Datagram Protocol (UDP) operates at the transport layer.

Which of the following protocols generate messages that are carried directly within Internet Protocol (IP) datagrams, with no intervening transport layer protocol? (Choose all correct answers.) A. ICMP B. IGMP C. SMTP D. SNMP

A and B. Internet Control Message Protocol (ICMP) and Internet Group Management Protocol (IGMP) are unusual in that they generate messages that are encapsulated directly within IP datagrams. Nearly all of the other TCP/IP protocols, including Simple Mail Transfer Protocol (SMTP) and Simple Network Management Protocol (SNMP), are encapsulated within one of the transport layer protocols—User Datagram Protocol (UDP) or Transmission Control Protocol (TCP)—which is encapsulated in turn within an IP datagram.

Which of the following port values are used by the File Transfer Protocol (FTP)? (Choose all correct answers.) A. 21 B. 23 C. 20 D. 53 E. 69

A and C. FTP uses two ports: one for control messages (port 21) and one for data transfers (port 20). Port 23 is used by Telnet. Port 53 is used by the Domain Name System (DNS). Port 69 is used by the Trivial File Transfer Protocol (TFTP).

Which of the following elements can be used to identify the devices in a particular VLAN? (Choose all correct answers.) A. Hardware addresses B. IP addresses C. DNS names D. Switch port numbers

A and D. Every network device has a unique hardware address coded into its network interface adapter, and administrators can use these addresses to select the devices that will be part of a specific virtual local area network (VLAN). When VLANs are implemented inside the switch, selecting the ports to which specific computers are attached is a simple way to identify the computers in a particular VLAN. IP addresses are layer 3 (network layer) constructs, so they do not apply to layer 2 (data link layer) devices like switches. Although DNS names do uniquely identify computers on a network, DNS is an application layer process and has nothing to do with the switching and routing processes, which occur at the data link and network layers. Therefore, you cannot use DNS names to identify the computers in a VLAN.

Which of the following statements about Routing Information Protocol version 1 (RIPv1) is true? (Choose all correct answers.) A. RIPv1 broadcasts the entire contents of the routing table every 30 seconds. B. RIPv1 advertises the subnet mask along with the destination network. C. RIPv1 broadcasts only the elements in the routing table that have changed every 60 seconds. D. RIPv1 does not include the subnet mask in its network advertisements.

A and D. Routers that are running the RIPv1 routing protocol broadcast their entire routing tables every 30 seconds, regardless of whether there has been a change in the network. RIP v1 does not include the subnet mask in its updates, so it does not support subnetting.

75 Which of the following statements about static routing are true? (Choose all correct answers.) A. Static routes are manually configured routes that administrators must add, modify, or delete when a change in the network occurs. B. Static routes are automatically added to the routing table by routing protocols when a new network path becomes available. C. Static routes adapt to changes in the network infrastructure automatically. D. Static routes are a recommended solution for large internetworks with redundant paths to each destination network. E. Static routes are a recommended solution for small internetworks with a single path to each destination network.

A and E. Administrators must manually add, modify, or delete static routes when a change in a network occurs. For this reason, static routes are not recommended for use in large internetworks where there are multiple paths to each destination network. Static routes are not automatically added by routing protocols and do not adapt to changes in a network.

Which of the following layers of the Open Systems Interconnection (OSI) model typically have dedicated physical hardware devices associated with them? (Choose all correct answers.) A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

A, B, and C. The physical layer of the OSI model is associated with hubs, cables, and network interface adapters. The data link layer is associated with bridges and switches. The network layer is associated with routers. The transport, session, presentation, and application layers are typically not associated with dedicated hardware devices.

Which of the following statements about the User Datagram Protocol (UDP) are true? (Choose all correct answers.) A. UDP does not use packet sequencing and acknowledgments. B. UDP uses packet sequencing and acknowledgments. C. UDP is a connection-oriented protocol. D. UDP is a connectionless protocol. E. UDP has an 8-byte header. F. UDP has a 20-byte header.

A, D, and E. UDP is a connectionless transport layer protocol. It has a small, 8-byte header and does not use packet sequencing or acknowledgments.

Which of the following is the default subnet mask for an IPv4 Class A network? A. 255.0.0.0 B. 255.255.0.0 C. 255.255.255.0 D. 255.255.255.255

A. A Class A address uses only the first octet as the network identifier, which yields a binary subnet mask of 11111111 00000000 00000000 00000000. In decimal form, the subnet mask is 255.0.0.0. The 255.255.0.0 mask is for Class B addresses, and 255.255.255.0 is for Class C addresses. Option D, 255.255.255.255, is the broadcast address for the current network.

Which of the following devices operates only at the physical layer of the Open Systems Interconnection (OSI) model? A. Hub B. Bridge C. Switch D. Router

A. A hub functions only at the physical layer by forwarding all incoming signals out through all of its ports. Bridges and switches operate at the physical layer and the data link layer by selectively propagating incoming data. Routers operate at the network layer by connecting local area networks and propagating only the traffic intended for another network, based on IP addresses.

An Ethernet network interface adapter provides functions that span which two layers of the Open Systems Interconnection (OSI) model? A. Physical and data link B. Data link and network C. Network and transport D. Transport and application

A. A network interface adapter functions at the data link layer by encapsulating network layer data for transmission over the network. It provides physical layer functions by providing the connection to the network medium and generating the appropriate signals for transmission.

Which of the following protocols is limited to use on the local subnet only? A. Address Resolution Protocol (ARP) B. Dynamic Host Configuration Protocol (DHCP) C. Domain Name System (DNS) D. Simple Mail Transfer Protocol (SMTP)

A. ARP relies on broadcast transmissions, which are not routable. It is therefore limited to use on the local subnet. DHCP also relies on broadcasts, but the ability to create DHCP relay agents makes it usable on an entire internetwork. DNS and SMTP do not rely on broadcasts and are therefore not limited to the local subnet.

Which of the following types of routing protocols route datagrams between autonomous systems? A. EGP B. RIP C. IGP D. OSPF

A. An Exterior Gateway Protocol (EGP) routes datagrams between autonomous systems. An Interior Gateway Protocol (IGP) routes datagrams within an autonomous systems. Routing Information Protocol (RIP) and Open Shortest Path First (OSPF) are examples of interior gateway protocols.

Which of the following statements is true about an Ethernet network that uses CSMA/CD? A. Collisions are a normal occurrence. B. Collisions never occur unless there is a network fault. C. Collisions cause data to be irretrievably lost. D. Collisions are the result of duplicate IP addresses.

A. Collisions are a normal occurrence on an Ethernet network; they occur when two nodes transmit at exactly the same time. There need not be a network fault for collisions to occur. When collisions occur, the nodes involved retransmit their packets so that no data is lost. Collisions are a phenomenon of data link layer protocols; they have nothing to do with IP addresses, which are network layer constructs.

What is the term for the process by which dynamic routing protocols update other routers with routing table information? A. Convergence B. Distance vectoring C. Redistribution D. Dissemination

A. Convergence is the term for the process by which routers propagate information from their routing tables to other routers on the network using dynamic routing protocols. Distance vectoring, redistribution, and dissemination do not describe this process.

Which of the following mechanisms for prioritizing network traffic uses a 6- bit classification identifier in the Internet Protocol (IP) header? A. Diffserv B. CoS C. Traffic shaping D. QoS

A. Differentiated services (Diffserv) is a mechanism that provides quality of service on a network by classifying traffic types using a 6-bit value in the differentiated services (DS) field of the IP header. Class of Service (CoS) is a similar mechanism that operates at the data link layer by adding a 3-bit Priority Code Point (PCP) value to the Ethernet frame. Traffic shaping is a means of prioritizing network traffic that typically works by delaying packets at the application layer. Quality of service (QoS) is an umbrella term that encompasses a variety of network traffic prioritization mechanisms.

An enterprise network has been designed with individual departmental switches because in most cases, the devices in a specific department exchange network traffic with other devices in the same department. Each of the departmental switches is also connected to a host switch, which enables devices to communicate with other departments. Which of the following terms describes this switching architecture? A. Distributed switching B. Port forwarding C. Traffic shaping D. Neighbor discovery

A. Distributed switching describes a hierarchical switching architecture in which remote switches (in this case departmental switches) handle most of the network traffic, with a host switch used only for traffic between the remote locations. Port forwarding is a routing method that redirects traffic intended for one IP address and port number to another. Traffic shaping is a series of techniques that optimize the allocation of network bandwidth. Neighbor discovery is an IPv6 technique used to find addresses of devices and services on the local network.

Which of the following TCP/IP routing protocols measures the efficiency of routes by the number of hops between the source and the destination? A. Routing Information Protocol (RIP) B. Open Shortest Path First (OSPF) C. Border Gateway Protocol (BGP) D. Intermediate System to Intermediate System (IS-IS)

A. RIP is a distance vector protocol, which uses hop counts to measure the efficiency of routes. OSPF, BGP, and IS-IS are all link state protocols, which do not rely on hop counts.

Which of the following TCP/IP routing protocols does not include the subnet mask within its route update messages, preventing it from supporting subnetting? A. Routing Information Protocol, version 1 (RIPv1) B. Routing Information Protocol, version 2 (RIPv2) C. Border Gateway Protocol (BGP) D. Open Shortest Path First (OSPF)

A. RIP v1 does not include the subnet mask in its updates. RIPv2 supports subnetting and includes the subnet mask of each network address in its updates. OSPF and BGP both include the subnet mask within their updates.

Which of the following is the primary application layer protocol used by web browsers to communicate with web servers? A. HTTP B. HTML C. SMTP D. FTP

A. The Hypertext Transfer Protocol (HTTP) is the primary protocol used for web client/server communications. Hypertext Markup Language is a coding language used to create web content. Simple Mail Transfer Protocol (SMTP) and File Transfer Protocol (FTP) can both be used in web communications, but neither is the primary protocol.

Which of the following IEEE standards calls for the use of the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) media access control mechanism? A. 802.11ac B. 802.1X C. 802.3 D. All of the above

A. The IEEE 802.11ac standard, like all of the wireless LAN standards in the 802.11 working group, uses CSMA/CA for media access control. The 802.1X standard defines an authentication mechanism and does not require a media access control mechanism. The IEEE 802.3 (Ethernet) standard uses Carrier Sense Multiple Access with Collision Detection (CSMA/CD).

What field in the Transmission Control Protocol (TCP) Option subheader specifies the size of the largest segment a system can receive? A. MSS B. Window C. MMS D. WinMS

A. The Maximum Segment Size (MSS) field in the TCP Options subheader specifies the size (in bytes) of the largest segment a system can receive. The Window field indicates the amount of data (in bytes) that the receiver can accept. There are no MMS or WinMS fields in a TCP header.

Which of the following protocols provides connection-oriented service with guaranteed delivery at the transport layer of the OSI model? A. TCP B. HTTP C. UDP D. IP

A. The Transmission Control Protocol (TCP) provides connection-oriented service at the transport layer, with guaranteed delivery. The User Datagram Protocol (UDP) provides connectionless service at the transport layer. Hypertext Transfer Protocol (HTTP) operates at the application layer, and Internet Protocol (IP) is a connectionless network layer protocol.

Which of the following pairs of well-known ports are the default values you would use to configure a POP3 email client? A. 110 and 25 B. 143 and 25 C. 110 and 143 D. 80 and 110 E. 25 and 80

A. The default port for the Post Office Protocol (POP3) is 110. The default port for the Simple Mail Transfer Protocol (SMTP), the other protocol used by email clients, is 25. Port 143 is the default for the Internet Message Access Protocol (IMAP), a different email mailbox protocol that clients never use with POP3. Port 80 is the default for the Hypertext Transfer Protocol (HTTP), which is not used by email clients.

Alice is a network administrator designing a new local area network (LAN). She needs to determine the type of cabling and the network topology to implement. Which layers of the Open Systems Interconnection (OSI) model apply to cabling and topology elements? A. Physical and data link layers B. Data link and network layers C. Network and transport layers D. Transport and application layers

A. The physical layer defines the mechanical and electrical characteristics of the cables used to build a network. The data link layer defines specific network (LAN or WAN) topologies and their characteristics. The physical layer standard that Alice will implement is dependent on the data link layer protocol she selects. The network, transport, and application layers are not concerned with cables and topologies.

Which layer of the Open Systems Interconnection (OSI) model is responsible for transmitting signals over the network medium? A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

A. The physical layer of the OSI model defines the functions specific to the network medium and the transmission and reception of signals. All of the other layers are implemented in software and do not physically send or receive signals.

Which layer of the Open Systems Interconnection (OSI) model defines the medium, network interfaces, connecting hardware, and signaling methods used on a network? A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

A. The physical layer of the OSI model defines the standards for the physical and mechanical characteristics of a network, such as cabling (copper and fiber), connecting hardware (hubs and switches), and signaling methods (analog and digital). All of the other layers are not involved in the mechanical characteristics of the network.

determine whether the receiving host has successfully received the sending host's data? A. ACK B. FIN C. PSH D. SYN E. URG

A. The receiving host uses the ACK bit to notify the sending host that it has successfully received data. The other control bits are not used to acknowledge receipt of information.

What is the term for the combination of an IPv4 address and a port number, as in the following example: 192.168.1.3:23? A. Socket B. OUI C. Well-known port D. Network address E. Domain

A. The term for an IPv4 address and port number in combination is socket. An organizationally unique identifier (OUI) identifies a manufacturer of networking hardware. A well-known port is a port number assigned to a specific application. A network address is the network identifier part of an IP address. A domain is a group of computers and other resources.

Which of the following IPv4 addresses are you unable to assign to a network host? (Choose all correct answers.) A. 1.1.1.1 B. 229.6.87.3 C. 103.256.77.4 D. 9.34.0.1

B and C. IPv4 addresses with first byte values from 224 to 239 are Class D addresses, which are reserved for use as multicast addresses. Therefore, you cannot assign 229.6.87.3 to a host. Option C, 103.256.77.4, is an invalid address because the value 256 cannot be represented by an 8-bit binary value. The other options, 1.1.1.1 and 9.34.0.1, are both valid addresses.

Some switches can perform functions associated with two layers of the Open Systems Interconnection (OSI) model. Which two of the following layers are often associated with network switching? (Choose all correct answers.) A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

B and C. The primary function of a switch is to process packets based on their media access control (MAC) addresses, which makes it a data link layer device. However, many switches can also perform routing functions based on IP addresses, which operate at the network layer.

Ralph is a network administrator who has just installed a new open source email server for the users at his company. The server is configured to send and receive Internet email and create a mailbox for each user that will permanently store the user's mail on the server. Ralph next uses a protocol analyzer to examine the network traffic resulting from the new server installation. Which of the following new protocols should Ralph expect to see in his network traffic analysis? (Choose all correct answers.) A. SNMP B. SMTP C. POP3 D. IMAP E. RIP

B and D. Ralph's traffic analysis should show the addition of the Simple Mail Transfer Protocol (SMTP), which handles incoming and outgoing Internet mail, and Internet Message Access Protocol (IMAP), which provides mailboxes for users who store their mail permanently on the server. POP3 is a mailbox protocol that enables users to download their messages and should therefore not be present on the network. SNMP is a network management protocol and RIP is a routing protocol; neither of them carries email traffic.

Which of the following statements about VLANs are true? (Choose all correct answers.) A. All of the devices in a particular VLAN must be physically connected to the same switch. B. A VLAN creates a limited broadcast domain on a switched network. C. You must have VLANs on a switched network for communication between computers on different cable segments to occur. D. A router is required for communication between VLANs.

B and D. The computers in a single virtual local area network (VLAN) can be located anywhere on a switched network, irrespective of the switches' physical configuration. A broadcast message generated by a computer in a VLAN is transmitted to all of the other computers in that VLAN only, just as if the systems were physically located on a separate LAN or subnet. Unicast transmissions between computers on a switched network do not require VLANs because the switches create what amounts to a direct connection between the two systems. VLANs are needed only for communication processes that require the use of broadcasts, which if transmitted without VLANs, would flood the network. Even though they are a purely logical construction, VLANs function just like physical subnets and require routers for communication between them. Routing capabilities are often integrated into switches to enable communication between VLANs.

Which of the following protocols use(s) the term datagram to describe the data transfer unit it creates? (Choose all correct answers.) A. Ethernet B. IP C. TCP D. UDP

B and D. The term datagram is typically used by protocols offering connectionless delivery service. The two main connectionless protocols in the TCP/IP suite are the Internet Protocol (IP) and the User Datagram Protocol (UDP), both of which use the term datagram. Ethernet uses the term frame, and Transmission Control Protocol (TCP) uses segment.

Which of the following are not valid IPv4 addresses in the private address space defined by RFC 1918? (Choose all correct answers.) A. 10.16.225.1 B. 172.33.19.7 C. 192.168.254.77 D. 10.255.255.255 E. 172.15.2.9

B and E. RFC 1918 defines the private address space as the following ranges: 10.0.0.0-10.255.255.255 172.16.0.0-172.31.255.255 192.168.0.0-192.168.255.255 Option B, 172:33:19:7, and Option E, 172.15.2.9, both fall outside the specified private Class B range and are therefore not valid private addresses.

Which of the following are terms for an area of an enterprise network, separated by firewalls, that contains servers that must be accessible both from the Internet and from the internal network? (Choose all correct answers.) A. Intranet B. DMZ C. EGP D. Stateless network E. Perimeter network

B and E. Servers that must be accessible both from the internal network and from the Internet are typically located in an area of the enterprise called a perimeter network or a demilitarized zone (DMZ). This area is separated from both the Internet and the internal network by firewalls, which prevents unauthorized internet users from accessing the internal network. Intranet is another term for the internal network. Edge Gateway Protocol (EGP) is a type of routing protocol, and stateless is a type of firewall; neither applies to this definition.

Which of the following is an example of a circuit-switched network connection, as opposed to a packet-switched network connection? A. Two wireless computers using an ad hoc topology B. A landline voice telephone call C. A smartphone connecting to a cellular tower D. Computers connected by a wired LAN

B. A circuit switched network connection requires a dedicated physical connection between the communicating devices. In a landline telephone call, a dedicated circuit is established between the two callers, which remains in place for the entire duration of the call. Wireless computers in an ad hoc topology and computers connected to a wired LAN use packet switching instead. A smartphone connection uses cell switching.

VLANs create the administrative boundaries on a switched network that are otherwise provided by which of the following devices? A. Hubs B. Routers C. Domains D. Bridges

B. Connecting subnets with routers at the network layer maintains the data link layer administrative boundaries that prevent broadcast transmissions from being propagated throughout the entire internetwork. Switching eliminates those data link layer boundaries, and administrators can use virtual local area networks (VLANs) to simulate them. Because hubs propagate all of the traffic they receive out through all of their ports indiscriminately, they create no administrative boundaries. Domains are logical groups of network devices defined by the Domain Name System (DNS). Their functions are not related to VLANs in any way. Switches are essentially multiport bridges that forward incoming traffic only to the device for which it is destined. Therefore, bridges are more closely related to eliminating administrative boundaries than to establishing them.

Which of the following is a protocol that identifies VLANs by inserting a 32- bit field in the Ethernet frame? A. IEEE 802.1P B. IEEE 802.1Q C. IEEE 802.1X D. IEEE 802.1AB

B. IEEE 802.1Q is a standard that defines a mechanism (called Ethernet trunking by some manufacturers) that identifies the virtual local area network (VLAN) to which a packet belongs by inserting an extra 32- bit field into its Ethernet frame. IEEE 802.1P is a standard that defines a mechanism for implementing quality of service (QoS) at the data link layer by adding a 3-bit field into Ethernet frames. IEEE 802.1X is a standard defining an authentication mechanism called port-based network access control (PNAC). IEEE 802.1AB is a standard defining the Link Layer Discovery Protocol (LLDP).

Network address translation (NAT) operates at which layer of the Open Systems Interconnection (OSI) model? A. Data link B. Network C. Transport D. Application

B. NAT works by modifying IP addresses, which are a network layer element. The data link layer is concerned only with communications on the local subnet and is not involved with NAT processing. Because NAT modifies only the IP packet headers, it works with any transport layer protocol. NAT also works with most TCP/IP applications because it operates below the application layer of the OSI model.

Which of the following services enables computers on a private IPv4 network to access the Internet using a registered IP address? A. DHCP B. NAT C. DNS D. NTP

B. Network Address Translation (NAT) is a service that enables computers with unregistered IP addresses to access the Internet by substituting a registered address in packets as they pass through a router. The Dynamic Host Configuration Protocol (DHCP) is an IP address allocation service. Domain Name System (DNS) resolves domain and hostnames into IP addresses, and Network Time Protocol (NTP) enables network devices to synchronize their time settings.

At which layer of the OSI model do you find the protocol responsible for the delivery of data to its ultimate destination on an internetwork? A. Data link B. Network C. Session D. Application

B. On a TCP/IP network, the Internet Protocol (IP) at the network layer is the protocol responsible for the delivery of data to its final destination. Data link layer protocols are only concerned with communication between devices on a local area network (LAN) or between two points connected by a wide area network (WAN). The session and application layers are not involved in the actual delivery of data.

At which of the Open Systems Interconnection (OSI) model layers do switches and bridges perform their basic functions? A. Physical B. Data link C. Network D. Transport

B. Switches and bridges are involved in local area network (LAN) communications only and therefore operate at the data link layer.

Which of the following explanations best describes the function of a Transmission Control Protocol (TCP) or User Datagram Protocol (UDP) port number? A. The port number indicates to the receiver that the sender can activate a specific port only. B. The port number is used by both the sender and the receiver to identify the application that generated the information in the datagram. C. The port number is used only by the receiver to indicate the application process running on the sender. D. The port number is used by both the sender and the receiver to negotiate a wellknown server port for the communicating processes.

B. TCP ports and UDP ports identify the application protocol or process that generated the information in a datagram. Client ports are chosen randomly from the range 1024 through 65,534. Server ports are wellknown and are chosen from the range 1 through 1023.

Which of the following TCP/IP parameters, configured on an end system, specifies the Internet Protocol (IP) address of a router on the local network that provides access to other networks? A. WINS Server Addresses B. Default Gateway C. DNS Server Addresses D. Subnet Gateway

B. The Default Gateway parameter specifies the address of the local router that the end system should use to access other networks. The WINS Server Addresses and DNS Server Addresses parameters are used to resolve names to IP addresses. There is no such parameter as Subnet Gateway.

At which of the following layers of the Open Systems Interconnection (OSI) model do the protocols on a typical local area network use MAC addresses to identify other computers on the network? A. Physical B. Data link C. Network D. Transport

B. The Ethernet (or IEEE 802.3) protocol at the data link layer uses MAC addresses to identify computers on the local network. Media access control (MAC) addresses are coded into the firmware of physical network interface adapters by the manufacturer. The physical layer deals with signals and is not involved in addressing. The IP protocol at the network layer has its own addressing system. The transport layer protocols are not involved in addressing

Which of the following organizations is responsible for assigning the wellknown port numbers used in transport layer protocol headers? A. Institute for Electronic and Electrical Engineers (IEEE) B. Internet Assigned Numbers Authority (IANA) C. Internet Engineering Task Force (IETF) D. International Organization for Standardization (ISO)

B. The IANA assigns values for well-known port numbers. The IEEE publishes Ethernet standards, among many others. The IETF develops standards for Internet technologies. The ISO developed the Open Systems Interconnection (OSI) model.

Which of the following protocols is used to exchange directory service information? A. RDP B. LDAP C. SNMP D. SMB

B. The Lightweight Directory Access Protocol (LDAP) is an application layer protocol used for managing and accessing information stored in directory services. Remote Desktop Protocol (RDP) is used to establish a graphical remote control session with another computer. Simple Network Management Protocol (SNMP) is used to carry information gathered by management agents distributed around a network to a central management server. Server Message Block (SMB) is the primary file sharing protocol used by Windows systems.

Which of the following is a network layer protocol that uses ICMPv6 messages to locate routers, DNS servers, and other nodes on an IPv6 network? A. BGP B. NDP C. OSPF D. PoE

B. The Neighbor Discovery Protocol (NDP) is a network layer protocol that defines five new Internet Control Message Protocol version 6 (ICMPv6) packet types, which enable IPv6 systems to locate resources on the network, such as routers and DNS servers, as well as autoconfigure and detect duplicate IPv6 addresses. Border Gateway Protocol (BGP) is an exterior gateway protocol that is designed to exchange routing information among autonomous systems. Open Shortest Path First (OSPF) is a link state routing protocol that enables routers to exchange routing table information. Power over Ethernet (PoE) is a general term for standards defining mechanisms for power delivery over Ethernet cables, along with data signals.

Which of the following protocols prevents network switching loops from occurring by shutting down redundant links until they are needed? A. RIP B. STP C. VLAN D. NAT

B. The Spanning Tree Protocol (STP) prevents packets from endlessly looping from switch to switch due to redundant links. Creating redundant links is a good preventive against switch failure, but packets transmitted over multiple links can circulate from switch to switch infinitely. STP creates a database of switching links and shuts down the redundant ones until they are needed. Routing Information Protocol (RIP) propagates routing table information. A virtual local area network (VLAN) is an organizational tool that operates within switches by creating multiple broadcast domains. Network Address Translation (NAT) is a routing method that enables private networks to share registered IP addresses.

Which of the following components does the port number in a transport layer protocol header identify? A. A transport layer protocol B. An application C. A gateway D. A proxy server

B. The port numbers specified in a transport layer protocol header identify the application that generated the data in the packet or the application that will receive the data. Port numbers do not identify transport layer protocols, gateways, or proxy servers.

Which layer of the Open Systems Interconnection (OSI) model would be responsible for converting a text file encoded using EBCDIC on the sending system into ASCII code, when required by the receiving system? A. Application B. Presentation C. Session D. Physical

B. The presentation layer of the OSI model is responsible for translating different kinds of syntax, including text-encoding systems, such as EBCDIC and ASCII. The application, session, and physical layers do not perform this function.

How many bits are allocated to the host identifier in an IPv4 address on the 10.72.0.0/17 network? A. 8 B. 15 C. 16 D. 17

B. The value after the slash in a classless inter-domain routing (CIDR) address specifies the number of bits in the network identifier. An IP address has 32 bits, so if 17 bits are allocated to the network identifier, 15 bits are left for the host identifier.

Which of the following is the range of IPv4 addresses that Automatic Private IP Addressing (APIPA) assigns to DHCP clients that cannot access a DHCP server? A. 10.0.0.0 to 10.0.255.255 B. 169.254.0.0 to 169.254.255.255 C. 192.168.0.0 to 192.168.0.255 D. 224.0.0.0 to 224.0.255.255

B. When a DHCP client cannot access a DHCP server, APIPA assigns it a Class B address in the range 169.254.0.0 to 169.254.255.255.

Ed is a software developer who has been given the task of creating an application that requires guaranteed delivery of information between end systems. At which layer of the Open Systems Interconnection (OSI) model does the protocol that provides the guaranteed delivery run, and what type of protocol must Ed use? A. Data link layer; connectionless B. Network layer; connection-oriented C. Transport layer; connection-oriented D. Application layer; connectionless

C. A connection-oriented transport layer protocol provides guaranteed delivery of data for upper layer applications. Connectionless protocols do not guarantee delivery of information and therefore are not a good choice. Guaranteed delivery of information is generally not a function of the data link, network, or application layer.

Which of the following best defines the concept of the dual stack? A. A computer with two network interface adapters B. A computer with two installed operating systems C. A computer with two sets of networking protocols D. A computer with connections to two different network segments

C. A dual stack is an IP implementation that includes both IPv4 and IPv6 protocol stacks, operating simultaneously. A computer with two network adapters or connections to two network segments is often called multihomed. A computer with two installed operating systems is called a dual-boot system.

Which of the following could be a valid MAC address for a network interface adapter? A. 10.124.25.43 B. FF:FF:FF:FF:FF:FF C. 00:1A:6B:31:9A:4E D. 03:AE:16:3H:5B:11 E. fe80::89a5:9e4d:a9d0:9ed7

C. A media access control (MAC) address is a six-byte hexadecimal value, with the bytes separated by colons, as in 00:1A:6B:31:9A:4E. Option A, 10.124.25.43, is all decimals and uses periods; this is an IPv4 address. Option B, FF:FF:FF:FF:FF:FF, is a valid MAC address, but this value is reserved for use as a broadcast address. Option D, 03:AE:16:3H:5B:11, is not a valid hexadecimal address, which should contain only numerals and the letters A to F. Option E, fe80::89a5:9e4d:a9d0:9ed7, is too long for a MAC address; this is a valid IPv6 address.

What is the valid range of numbers for the ephemeral client ports used by the Transmission Control Protocol (TCP) and User Datagram Protocol (UDP)? A. 1023 through 65534 B. 1 through 1024 C. 49152 through 65535 D. 1024 to 49151

C. Ephemeral client ports fall in the range of 49152 through 65535. Well-known TCP and UDP server ports fall in the range of 1 through 1023. Registered port numbers fall in the range from 1024 to 49151.

Flow control is a function implemented in protocols operating at which layer of the Open Systems Interconnection (OSI) model? A. Presentation B. Session C. Transport D. Network

C. Flow control is a process that adjusts the transmission rate of a protocol based on the capability of the receiver. If the receiving system becomes overwhelmed by incoming data, the sender dynamically reduces the transmission rate. In the TCP/IP protocol suite, Transmission Control Protocol (TCP) is responsible for implementing flow control. TCP runs at the transport layer. None of the other layers listed have TCP/IP protocols that provide flow control.

Which layer of the Open Systems Interconnection (OSI) model is responsible for the logical addressing of end systems and the routing of datagrams on a network? A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

C. Network layer protocols specify logical addresses for end system communication and route datagrams across a network. The physical layer defines standards for physical and mechanical characteristics of a network. The data link layer uses media access control (MAC) or hardware addresses, not logical addresses. The transport layer uses port numbers, not logical addresses. Session layer protocols create and maintain a dialogue between end systems. Presentation layer protocols are responsible for the formatting, translation, and presentation of information. The application layer provides an entry point for applications to access the protocol stack and prepare information for transmission across a network.

74 Which of the following is not an advantage of packet switching over circuit switching? A. Packets can be transmitted out of order. B. Packets can take different routes to the destination. C. Packets can be stored temporarily in the event of network congestion. D. Packets can be routed around areas of network congestion.

C. On a packet-switched network, packets can take different routes to the destination, can be transmitted out of order, and can be routed around network congestion. The packets are then reassembled into a complete message once all of them reach the destination. Temporary message storage is an advantage of circuit switching networks.

Which of the following protocols does the Ping utility use to exchange messages with another system? A. UDP B. TCP C. ICMP D. IGMP

C. Ping uses the Internet Control Message Protocol (ICMP) to exchange messages with other systems. ICMP is also used to return error messages to sending systems. The User Datagram Protocol (UDP) and the Transmission Control Protocol (TCP) are both transport layer protocols that carry application layer data; Ping does not use either one. The Internet Group Management Protocol (IGMP) is used to create multicast groups; Ping does not use it.

Which of the following is the default well-known port number for the Hypertext Transfer Protocol (HTTP) used for web client/server communications? A. 22 B. 20 C. 80 D. 1720

C. Port 80 is the default well-known port for HTTP. Port 22 is for the Secure Shell (SSH) protocol, port 20 is for File Transfer Protocol (FTP), and 1720 is for the H.323 audio/video-conferencing protocol.

Which of the following devices is used to physically connect computers in the same VLAN? A. A bridge B. A hub C. A switch D. A router

C. Replacing routers with switches turns an internetwork into a single large subnet, and virtual local area networks (VLANs) exist as logical elements on top of the switching fabric. Although VLANs are the functional equivalent of network layer subnets, the systems in a single VLAN are still physically connected by switches, not routers. Bridges connect network segments at the data link layer and selectively forward traffic between the segments. However, bridges do not provide a dedicated connection between two systems like a switch does, and they do not make it possible to convert a large routed internetwork into a single switched network. Therefore, they have no role in implementing VLANs. Hubs are physical layer devices that propagate all incoming traffic out through all of their ports. Replacing the routers on an internetwork with hubs would create a single shared broadcast domain with huge amounts of traffic and many collisions. Hubs, therefore, do not connect the computers in a VLAN.

Each of the following Carrier Sense Multiple Access with Collision Detection (CSMA/CD) events occurs on an Ethernet network when two stations transmit simultaneously, although not in the order listed. Which of the following events occurs immediately after the collision? A. The two stations observe a random back-off interval. B. The two stations transmit a jam signal. C. The two stations stop transmitting. D. The two stations listen to see if the channel is idle. E. The two stations begin retransmitting their frames.

C. Stations on a CSMA/CD network first check the medium to see if it's idle. If they detect an idle medium, they begin transmitting. If two or more devices transmit at the same time, a collision occurs. Immediately after a collision occurs, the two stations involved stop transmitting and then send out a jam signal. Then, the two stations back off for a random interval, and the transmission process begins again.

Which of the following protocols appears on the network as a service that client computers use to resolve names into IP addresses? A. DHCP B. BOOTP C. DNS D. SNMP

C. The Domain Name System (DNS) is a protocol that computers on a TCP/IP network use to resolve host and domain names into the IP addresses they need to communicate. Dynamic Host Configuration Protocol (DHCP) and Bootstrap Protocol (BOOTP) are both IP address allocation protocols, and Simple Network Management Protocol (SNMP) carries information gathered by agents to a central management console.

Identify the layer of the Open Systems Interconnection (OSI) model that controls the addressing, transmission, and reception of Ethernet frames, and also identify the media access control method that Ethernet uses. A. Physical layer; Carrier Sense Multiple Access with Collision Detection (CSMA/CD) B. Physical layer; Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) C. Data link layer; CSMA/CD D. Data link layer; CSMA/CA

C. The Ethernet protocol that handles the addressing, transmission, and reception of frames operates at the data link layer. Each frame includes hardware addresses that identify the sending and receiving systems on the local network. Ethernet uses the CSMA/CD media access control method. Physical layer specifications include the transmission of signals in the form of electrical or light pulses to represent binary code, not frames. CSMA/CA is a data link layer media access control method used by wireless LAN protocols, but not Ethernet.

Which of the following is a valid IPv6 address? A. fe00::b491:cf79:p493:23ff B. Nessus2001:0:49e6:39ff:8cf5:6812:ef56 C. fe00::c955:c944:acdd:3fcb D. 2001:0:44ef68:23eb:99fe:72bec6:ea5f

C. The address fe00::c955:c944:acdd:3fcb is correctly formatted for IPv6, with the double colon replacing three blocks of zeroes. Uncompressed, the address would appear as follows: fe00:0000:0000:0000:c955:c944:acdd:3fcb. Option A contains a nonhexadecimal digit. Option B contains only seven 16-bit blocks (and no double colon) instead of the eight required for 128 bits. Option D contains blocks larger than 16 bits.

Which of the following Transmission Control Protocol (TCP) control bits is set to 1 to initiate the termination of a session? A. SYN B. URG C. FIN D. END E. PSH

C. The termination phase of a TCP connection begins when either the client or the server sends a message containing the FIN control bit with a value of 1. The other control bits listed have nothing to do with the connection termination procedure, and there is no END bit.

Alice has been instructed to create a network with 8 subnets and 30 hosts per subnet. She has been assigned a Class C network address. Which of the following subnet masks will she have to use? A. 255.255.255.128 B. 255.255.255.192 C. 255.255.255.224 D. 255.255.255.240 E. 255.255.255.248 F. 255.255.255.252

C. To create a network with 8 subnets and 30 hosts per subnet, Alice would have to allocate 3 of the 8 bits in the last octet for subnet identifiers. This would result in a binary value of 11100000 for the last octet in the subnet mask, which converts to a decimal value of 224.

The protocols at which layer of the Open Systems Interconnection (OSI) model use port numbers to identify the applications that are the source and the destination of the data in the packets? A. Application B. Presentation C. Transport D. Network

C. Transport layer protocols, such as Transmission Control Protocol (TCP) and User Datagram Protocol (UDP), have header fields that contain the port numbers of the applications that generated the data in the packet and that will receive it. The application, presentation, and network layers do not use port numbers.

Which of the following is the most accurate description of the subnetting process on a TCP/IP network? A. You extend the IP address by adding bits for a subnet identifier. B. You borrow bits from the network identifier to create a subnet identifier. C. You borrow bits from the host identifier to create a subnet identifier. D. You create a subnet identifier by borrowing half of the bits from the network identifier and half from the host identifier.

C. You cannot extend the IP address beyond its 32-bit size, and you cannot remove bits from the network identifier, or the packets will not be routed properly. You must therefore create a subnet by borrowing bits from the host identifier.

Which of the following devices typically operates at the network layer of the Open Systems Interconnection (OSI) model? A. Proxy server B. Hub C. Network interface adapter D. Router

D. A router connects networks together at the network layer of the OSI model. Proxy servers operate at the application layer. Network interface adapters operate at both the data link and the physical layers. Hubs are physical layer devices.

In which IPv4 class is the address 127.0.0.1 found? A. Class A B. Class B C. Class C D. None of the above

D. Address 127.0.0.1 is the designated IPv4 local loopback address, and as such, it is reserved. It falls between Class A, which has first octet values from 1 to 126, and Class B, which has first octet values of 128 to 191.

Which of the following terms refers to a routing protocol that does not rely on hop counts to measure the efficiency of routes? A. Interior gateway protocol B. Edge gateway protocol C. Distance vector protocol D. Link state protocol

D. Distance vector protocols rely on hop counts to evaluate the efficiency of routes. Link state protocols use a different type of calculation, usually based on Dijkstra's algorithm. The terms interior gateway protocol and edge gateway protocol do not refer to the method of calculating routing efficiency.

Which of the following protocols operates at the network layer of the OSI model but does not encapsulate data generated by an upper layer protocol for transmission over the network? A. IP B. UDP C. ARP D. ICMP E. TCP

D. Internet Control Message Protocol (ICMP) operates at the network layer by sending operational and error messages. It does not encapsulate upper layer protocol data. Internet Protocol (IP) operates at the network layer, but it does encapsulate transport layer protocol data. Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) are transport layer protocols that encapsulate upper layer protocol data. Address Resolution Protocol (ARP) does not encapsulate upper layer protocol data, but it is a data link layer protocol.

Which of the following is not a protocol operating at the network layer of the OSI model? A. IP B. ICMP C. IGMP D. IMAP

D. Internet Protocol (IP), Internet Control Message Protocol (ICMP), and Internet Group Message Protocol (IGMP) are all network layer protocols. Internet Message Access Protocol (IMAP) is a mail protocol that operates at the application layer.

Which of the following terms refers to methods by which network traffic is prioritized to prevent applications from suffering faults due to network congestion? A. Port forwarding B. Dynamic routing C. VLANs D. QoS

D. Quality of service (QoS) is a general term that refers to various mechanisms for prioritizing network traffic so that applications or data streams requiring a certain level of performance are not negatively affected by lower-priority transmissions. Port forwarding is a routing method that redirects traffic intended for one IP address and port number to another. Dynamic routing is a method by which routing tables are automatically updated with new information as the routing fabric of an internetwork changes. Virtual local area networks (VLANs) are a means for partitioning a broadcast domain into discrete units that are functionally equivalent to physical LANs.

Which of the following server applications use two well-known port numbers during a typical transaction? A. NTP B. SNMP C. HTTP D. FTP

D. The File Transfer Protocol (FTP) uses two port numbers. It uses the first, port 21, for a control connection that remains open during the entire client/server session. The second port, 20, is for a data connection that opens only when the protocol is actually transferring a file between the client and the server. Network Time Protocol (NTP), Simple Network Management Protocol (SNMP), and Hypertext Transfer Protocol (HTTP) all use a single port on the server.

A client on a TCP/IP network is attempting to establish a session with a server. Which of the following correctly lists the order of Transmission Control Protocol (TCP) session establishment messages? A. SYN, ACK, SYN, ACK B. SYN, SYN, ACK, ACK C. SYN/ACK, SYN/ACK D. SYN, SYN/ACK, ACK

D. The TCP connection establishment exchange is a three-way handshake. The first frame contains a SYN message from the client, the second frame contains a SYN/ACK message from the server, and the last frame contains an ACK message from the client.

What is the native file sharing protocol used on all Microsoft Windows operating systems? A. Hypertext Transfer Protocol (HTTP) B. Network File System (NFS) C. File Transfer Protocol (FTP) D. Server Message Block (SMB) E. Lightweight Directory Access Protocol (LDAP)

D. The default file sharing protocol used on all Windows operating systems is SMB. HTTP is the native protocol used by web clients and servers. NFS is the native file sharing protocol used on Unix/Linux networks. FTP is a protocol used for transferring files from one system to another. LDAP is a protocol for transmitting directory service information.

Which of the OSI model layers is responsible for syntax translation and compression or encryption? A. Data link B. Network C. Session D. Presentation E. Application

D. The presentation layer provides a syntax translation service that enables two computers to communicate, despite their use of different bit-encoding methods. This translation service also enables systems using compressed or encrypted data to communicate with each other.

The secured version of the Hypertext Transfer Protocol (HTTPS) uses a different well-known port from the unsecured version. Which of the following ports is used by HTTPS by default? A. 25 B. 80 C. 110 D. 443

D. The well-known port for HTTPS is 443. Port 25 is for the Simple Mail Transfer Protocol (SMTP), port 80 is for unsecured HTTP, and port 110 is for the Post Office Protocol (POP3).

At which layer of the Open Systems Interconnection (OSI) model are there TCP/IP protocols that can provide either connectionless or connectionoriented services to applications? A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

D. There are two types of transport layer protocols: connection-oriented and connectionless. Connectionoriented protocols guarantee the delivery of data from source to destination by creating a connection between the sender and the receiver before any data is transmitted. Connectionless protocols do not require a connection between end systems in order to pass data. The physical layer does not use connectionless or connection-oriented protocols; it defines standards for transmitting and receiving information over a network. The data link layer provides physical addressing and final packaging of data for transmission. The network layer is responsible for logical addressing and routing. The session layer is responsible for creating and maintaining a dialogue between end systems. The presentation layer is responsible for the formatting, translation, and presentation of information. The application layer provides an entry point for applications to access the protocol stack and prepare information for transmission across a network.

Which of the following terms describes the Transmission Control Protocol (TCP) exchange that establishes a connection prior to the transmission of any data? A. Synchronization B. Initialization exchange C. Connection establishment D. Three-way handshake

D. Two systems establishing a TCP connection exchange three messages before they begin transmitting data. The exchange of these synchronization messages is referred to as a three-way handshake. The other terms listed are not formally used to describe this exchange.

What is the valid range of numbers for the well-known Transmission Control Protocol (TCP) and User Datagram Protocol (UDP) ports used by servers? A. 1024 through 49151 B. 1 through 49151 C. 49152 through 65534 D. 1 through 1023

D. Well-known TCP and UDP server ports fall in the range of 1 through 1023. Registered port numbers fall in the range from 1024 to 49151. Ephemeral client ports fall in the range of 49152 through 65535.

Alice has been instructed to install 100 Windows workstations, and she is working on automating the process by configuring the workstations to use PXE boots. Each workstation therefore must obtain an IP address from a DHCP server and download a boot image file from a TFTP server. Which of the following well-known ports must Alice open on the firewall separating the workstations from the servers? (Choose all correct answers.) A. 65 B. 66 C. 67 D. 68 E. 69

Dynamic Host Configuration Protocol (DHCP) servers use port numbers 67 and 68. The Trivial File Transfer Protocol (TFTP) uses port number 69. Neither protocol uses port 65 or 66.

Which layers of the Open Systems Interconnection (OSI) model do not have protocols in the TCP/IP suite exclusively dedicated to them? (Choose all correct answers.) A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

E and F. In the TCP/IP suite, the functions of the session layer are primarily implemented in the transport layer protocols: Transmission Control Protocol (TCP) and User Datagram Protocol (UDP). The presentation layer functions are often implemented in application layer protocols, although some functions, such as encryption, can also be performed by transport or network layer protocols.

Which of the following organizations developed the Open Systems Interconnection (OSI) model? A. International Telecommunication Union (ITU-T) B. Comité Consultatif International Télégraphique et Téléphonique (CCITT) C. American National Standards Institute (ANSI) D. Institute of Electrical and Electronics Engineers (IEEE) E. International Organization for Standardization (ISO)

E. ISO developed and published the OSI model to serve as a conceptual model for software and hardware developers. The ITU-T, formerly known as the CCITT, coordinates the development and advancement of international telecommunication networks and services. ANSI is a private organization that administers and coordinates a United States-based standardization and conformity assessment system. The IEEE publishes standards that define data link and physical layer standards. These standards are referred to collectively as the 802 series.

Which of the following is a correct listing of the Open Systems Interconnection (OSI) model layers, in order, from top to bottom? A. Physical, data link, transport, network, session presentation, application B. Application, session, presentation, transport, network, data link, physical C. Presentation, application, transport, session, network, physical, data link D. Session, application, presentation, transport, data link, network, physical E. Application, presentation, session, transport, network, data link, physical

E. The correct order of the OSI model layers, from top to bottom, is application, presentation, session, transport, network, data link, physical.

Which layer of the Open Systems Interconnection (OSI) model is responsible for dialogue control between two communicating end systems? A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

E. The session layer is responsible for creating and maintaining a dialogue between end systems. This dialogue can be a two-way alternate dialogue that requires end systems to take turns transmitting, or it can be a two-way simultaneous dialogue in which either end system can transmit at will. No other layers of the OSI model perform dialogue control between communicating end systems.

Which of the following values could a web client use as an ephemeral port number when communicating with a web server? A. 1 B. 23 C. 80 D. 1024 E. 1999 F. 50134

F. An ephemeral port number is a temporary port supplied by a client to a server, for use during a single session or transaction. The allowed ephemeral port number values range from 49152 to 65535. The port values below 1024 are reserved for use as well-known ports, and the values from 1024 to 49151 are reserved for ports registered by specific manufacturers for their applications. Of these answers, 50134 is the only value that the client can use as an ephemeral port.

What layer of the Open Systems Interconnection (OSI) model is responsible for translating and formatting information? A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

F. The presentation layer implements functions providing formatting, translation, and presentation of information. No other layers of the OSI model translate and format application data.

Which layer of the Open Systems Interconnection (OSI) model provides an entrance point to the protocol stack for applications? A. Physical B. Data link C. Network D. Transport E. Session F. Presentation G. Application

G. The application layer provides an entry point for applications to access the protocol stack and prepare information for transmission across a network. All other layers of the OSI model reside below this layer and rely on this entry point.