1. What ordering of TCP flags make up the Three-Way Handshake?
Answers
· SYN, SYN/ACK, ACK
· SYN, ACK, FIN
· FIN, FIN/ACK, ACK
· SYN, ACK, SYN, ACK
2. Transport layer protocols, like TCP and UDP, introduce the concept of a port. How many bits are in a port field?
Answers
· 32
· 8
· 4
· 16
Explanation: Because the port field in TCP and UDP headers consists of 16 bits, it is capable of representing port numbers in the range of 0 to 65535. This enables a diverse selection of alternative port assignments that may be used for a variety of communication functions. Higher port numbers are often allocated for dynamically issued or private uses, whereas port numbers lower than 1024 are typically designated for well-known service protocols.
3. A device that blocks traffic that meets certain criteria is known as a ________.
Answers
· Firewall
· Hub
· Router
· Switch
Explanation: A firewall is a piece of hardware that restricts traffic depending on predetermined rules and conditions. Firewalls are a kind of network security device that monitor and restrict network traffic coming into and going out of a network depending on certain security criteria that have been defined. They may take the form of hardware devices, software programs, or a mix of the two, and their primary function is to create a barrier between a trusted internal network and an untrusted external network such as the internet. This barrier may take the form of either a hardware device or a software application. Firewalls have the ability to filter and prohibit traffic based on a wide variety of criteria, such as IP addresses, port numbers, and particular content or protocols.
4. Which TCP flag is used to make the listening program respond immediately?
Answers
· URG
· ACK
· PSH
· RST
Explanation: The URG (Urgent) flag is a kind of TCP flag that may be used to force an urgent response from the listening application. When the URG flag in a TCP segment is set, it signifies that the significance of the urgent pointer field can no longer be ignored. The urgent pointer directs attention to the conclusion of the urgent data included inside the segment.
This flag is intended to signal to the receiving software that the data should be processed as quickly as possible. Typically, the usual processing would be interrupted so that the urgent data may take precedence. It's a means for the sender to let the receiver know that specific data in the segment has to be handled with quick attention or priority, and it's a way that the sender may communicate this to the receiver.
5. _________are identified as ports 49152 through 65535.
Answers
· Sockets
· System ports
· User ports
· Ephemeral ports
Explanation: Ports with numbers ranging from 49152 all the way up to 65535 are often referred to as "private" or "dynamic" ports. When an application or process needs to create a connection to a network, it will often choose a port from this range since these ports are used for communication that is either dynamic or private. It is standard practice to utilize them for ephemeral or transitory purposes, such as client-side communication with servers on well-known ports. They are not allocated to any particular application by the Internet allocated Numbers Authority (IANA), and they are not used for any other reason.
6. Unlike our five-layer model, the OSI network model adds two more layers on top of the Application Layer. Select examples of these new layers below.
Answers
· The presentation layer
· The interconnection layer
· The session layer
· The compression layer
7. An example of something that operates at the application layer is:
Answers
· UDP
· TCP
· A web browser
· A router
Explanation: Web browsers are the prototypical example of applications that function at the application layer of the OSI model. When you use a web browser such as Chrome, Firefox, or Safari, you are interacting with an application that operates at the application layer, which is the topmost tier in the networking stack.
Web browsers provide users the ability to access the numerous services and resources available on the internet, such as websites, web pages, and online apps, and to interact with those resources. In order to interface with web servers and access online information, they make use of application layer protocols such as HTTP (Hypertext Transfer Protocol) and HTTPS (Hypertext Transfer Protocol Secure).
Therefore, whenever you engage with an application that operates at the application layer of the OSI model, such as when you are browsing the web, checking your email, or using other services that are based on the internet, you are doing so through a web browser.
8. What's the standard number for a TTL field?
Answers
· 8
· 16
· 32
· 64
Explanation: The Time-to-Live (TTL) field of an IP (Internet Protocol) packet is an 8-bit field that reflects the maximum number of hops (routers) that a packet is permitted to travel before it is discarded. This field determines whether or not a packet is allowed to continue its journey across the network. 64 is the default value to use as the first setting for the TTL field.
This implies that the TTL field of a packet is set to 64 when it is transmitted, and the value of the TTL field is decreased by 1 each time the packet travels through a router. When the time to live (TTL) field hits zero, the packet is thrown away, and an ICMP (Internet Control Message Protocol) message may be sent back to the source to indicate that the packet has run out of time.
It is standard practice to use 64 as the default beginning value; however, this amount may be changed to a variety of other values based on the operating system or the network settings.
9. Which part of the operating system does the application use to communicate the need to establish a TCP connection?
Answers
· ARP message
· Networking stack
· The source port
· The router
Explanation: Whenever an application wants to create a TCP (Transmission Control Protocol) connection, it will normally make use of a series of system functions that are made available by the networking stack of the operating system. These system calls are the means by which the application initiates communication with the operating system in order to begin the process of establishing a TCP connection.
Socket APIs, which stand for Application Programming Interfaces, are used in the vast majority of programming environments to enable applications to communicate with operating systems. The particular system calls for establishing a TCP connection include methods such as socket(), which can be used to construct a socket; bind(), which can be used to associate the socket with a local address; connect(), which can be used to make a connection to a distant address; and listen(), which can be used by a server to begin listening for incoming connections.
These system calls serve as a bridge between the networking capabilities of the operating system and the application, enabling the program to express its networking requirements and create TCP connections for the purpose of data exchange.
10. Which section of the TCP/IP Five-Layer Network Model contains the data the application wants to send?
Answers
· The payload section of the Ethernet frame
· The payload section of the IP Datagram
· The payload of the TCP segment
· The header of the Ethernet frame
Explanation: The "Application Layer" is the component of the TCP/IP Five-Layer Network Model that holds the data that the application wishes to convey. The Application Layer is the very last layer in the paradigm, and it is the one that is in charge of delivering network services directly to applications or end users.
The Application Layer is where data that was created by an application, such as a web browser or email client, may be found. At this tier, the application is responsible for formatting the data and maintaining communication with the layers below it in order to guarantee accurate transmission across the network.
Encapsulation is a process that occurs when data travels down the levels of the TCP/IP architecture. This process involves each layer adding the header information that is specific to that layer to the payload. At some point, the data will be divided into packets at one of the lowest levels, and then they will be sent across the network.
11. The transport layer handles multiplexing and demultiplexing through what type of device?
Answers
· Switches
· Hubs
· Routers
· Ports
Explanation: The transport layer is responsible for multiplexing and demultiplexing, and it does so by using "ports." Within a single networking device, differentiating between several communication streams is accomplished via the use of ports.
Multiplexing is the process of merging numerous data streams into a single stream, while demultiplexing is the process of separating the separate streams from the combined stream. Multiplexing and demultiplexing are also referred to as the process of multiplexing.
Each communication endpoint (such as an application or process) is identified in the context of the transport layer by a combination of an IP address and a port number. This may be done in a variety of ways. The combination of an IP address and a port number makes it possible to identify individual communication streams in a way that is completely unique.
For instance, the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP) in the TCP/IP protocol suite employ port numbers to differentiate between the many services or applications that are operating on a device. The transport layer utilizes the port number to demultiplex the incoming packets and then delivers them to the relevant application or process when data is received.
12. Which field in the TCP header provides the information for the receiving network device to understand where the actual data payload begins?
Answers
· Checksum
· Data offset
· Acknowledgement number
· Sequence number
Explanation: The "Data Offset" or "Header Length" field is the part of the TCP (Transmission Control Protocol) header that contains the information that tells the network device that is receiving the data where the actual data payload begins. This information is provided in the TCP header. This field provides a 32-bit word representation of the total length of the TCP header.
The beginning location of the data inside the TCP segment is indicated by the value included in the Data Offset field. This field assists the receiving device in locating the beginning of the actual data payload by allowing it to account for the fact that the length of the TCP header can change depending on the presence of optional fields.
The Data Offset field consists of four bits, and the value contained inside these bits is multiplied by 32 bits in order to calculate the entire length of the TCP header. This, in turn, contributes to the process of locating the data inside the TCP segment by helping to determine its location.
13. A device involved in a Transmission Control Protocol (TCP) connection is ready to close the connection. The other device in the connection agrees. What has occurred?
Answers
· Two-way handshake
· Three-way handshake
· Handshake
· Four-way handshake
14. If a TCP socket is ready and listening for incoming connections, it's in the ______ state.
Answers
· CLOSE_WAIT
· ESTABLISHED
· SYN_SENT
· LISTEN
Explanation: When a TCP socket is in the "LISTEN" state, it means that it is prepared to accept new connections and is actively listening for them. In the context of the TCP protocol, the LISTEN state denotes the status of a server socket that is actively listening for connection requests from clients. This kind of server socket is said to be in the "listen" state. When a client wishes to create a connection with the server, it sends a SYN (Synchronize) segment, and the server switches from the LISTEN state to the state that corresponds to an established connection when it receives this segment.
15. A communication sent through Transmission Control Protocol (TCP) arrives out of order. What allows the data to be put back together in the correct order?
Answers
· Acknowledgement number
· Sequence numbers
· Checksum
· Preamble
Explanation: The use of sequence numbers and acknowledgment numbers is the method that is utilized by Transmission Control Protocol (TCP), and it is this process that enables out-of-order segments to be reassembled in the appropriate order. Every TCP segment has its own unique sequence number, which pinpoints exactly where in the stream the data being sent is located.
Before transferring the data to the higher-layer application, the receiving TCP stack will utilize the sequence numbers to rearrange the segments if they come out of order. It is the job of the acknowledgment numbers included inside the TCP header to both advise the sender about the next anticipated sequence number and to acknowledge the reception of individual segments.
The sender resends any segments that are not recognized by the recipient, which enables the receiver to reconstruct any segments that were lost or received out of order. This procedure, in conjunction with the use of sequence and acknowledgment numbers, helps to assure the dependable and well-organized transmission of data inside a TCP connection.
16. In the OSI network model, the ________ is responsible for facilitating the communication between actual applications and the transport layer.
Answers
· session layer
· application layer
· physical layer
· presentation layer
Explanation: The "Application Layer" of the OSI network model is the part of the model that is in charge of allowing communication between the real applications and the transport layer. The Application Layer is the layer that sits between the software programs that need network services and the network itself. It offers network services directly to end users or applications and acts as the interface between the two.
The Application Layer is responsible for a variety of functions, including the provision of network access to application software, the facilitation of communication and the exchange of data between multiple applications, and the provision of a variety of network services, including file transfer, electronic mail, and remote login.
The Application Layer is essentially the layer that is responsible for user interfaces as well as application-level protocols, which makes it possible for software programs to connect with one another across a network.
17. You are sending a very small amount of information that you need the listening program to respond to immediately. Which Transmission Control Protocol (TCP) flag will be used?
Answers
· ACK
· RST
· PSH
· URG
Explanation: You might use the "Urgent" (URG) flag in a Transmission Control Protocol (TCP) transmission if you require the listening application to reply promptly to a very little quantity of information in the event that the information is sent over the protocol. The TCP header has a flag called URG that, when set, indicates that the data in the TCP segment is very time-sensitive and demands quick attention.
When the URG flag is set, it is often accompanied by an urgent pointer field in the TCP header that identifies the end of the urgent data. This field indicates where the data will be dropped if it is not sent immediately. Because of this, the sender is able to indicate to the recipient that certain data included inside the segment is either time-sensitive or needs priority processing.
Keep in mind that the usage of the URG flag is application-dependent, and that in order for communication to take place effectively, both the transmitting application and the receiving application need to support and comprehend it.
18. What layer of the TCP/IP Five-Layer Network Model allows applications to communicate in a way they understand?
Answers
· Data layer
· User layer
· Application layer
· Transport layer
Explanation: The "Application Layer" is the name given to the part of the TCP/IP Five-Layer Network Model that facilitates communication between programs in a format that those apps can comprehend. The Application Layer is the very last layer in the paradigm, and it serves as a platform that enables different software programs to connect with one another across a network.
This layer is in charge of delivering network services straight to end users or applications and is accountable for doing so. It incorporates a wide variety of protocols and services that make it possible for applications to connect with one another, comprehend the data formats used by one another, and share information. The Hypertext Transfer Protocol (also known as HTTP), the File Transfer Protocol (often known as FTP), the Simple Mail Transfer Protocol (also known as SMTP), and many more protocols are examples of application layer protocols.
In a nutshell, the Application Layer serves as the interface between the actual software programs and the network itself, making it possible for the two to interact with one another in a manner that is clear to both parties.
19. What port does the File Transfer Protocol (FTP) typically listen on?
Answers
· 21
· 80
· 443
· 25
When it is operating in active mode, the FTP server will check for incoming data connections on port 20. When using passive mode, the server chooses a port for the client to connect to, and the client then transfers data using the port that was chosen by the server. On the other hand, port 21 is always used for the connection that controls the system and is where instructions and replies are traded.
Answers
· TCP
· address
· sequence
· acknowledgement
Explanation: The term "sequence number" refers to a 32-bit value that determines where you are in the progression of TCP segments. This number is used to keep track of where you are in the progression. The sequence number is an essential component of TCP connection because it plays an important role in preserving the order of sent data and ensuring its trustworthiness.
In the header of every TCP segment is a sequence number field, and the value of this field shows where the data fits in the larger context of the entire sequence of data that is being broadcast. The TCP stack that is doing the receiving utilizes the sequence numbers to appropriately organize and reassemble the segments that it has received. This ensures that the data is sent correctly to the application that is operating at a higher tier.
Shuffle Q/A 1
21. The concept of taking traffic that’s all aimed at the same node and delivering it to the proper receiving service is known as _________.
Answers
· encapsulation
· multiplexing
· routing
· demultiplexing
When it comes to networking, multiplexing is a technique that assists in the process of directing various forms of communication (for example, those coming from distinct applications or services) to the correct location on a node or network. This procedure guarantees that data coming from a variety of sources may be sent and received continuously without being disrupted by interference.
Answers
· Checksum
· Data offset
· Sequence number
· Acknowledgement number
Explanation: The "Acknowledgment Number" field is the part of the header of a Transmission Control Protocol (TCP) packet that contains the information about the next anticipated segment. The sequence number of the next data byte that the receiver is anticipating receiving from the sender is stored in the Acknowledgment Number field.
The receiver of a TCP segment will check the field labeled "Acknowledgment Number" whenever it receives a TCP segment in order to ascertain which subsequent segment should be anticipated. Due to the fact that the receiver confirms the reception of segments and notifies the sender about the next anticipated sequence number, this makes it possible for data to be sent across a TCP connection in a reliable and well-organized manner.
23. A Transmission Control Protocol (TCP) connection is established and two devices ensure that they're speaking the same protocol. What has occurred?
Answers
· Four-way handshake
· Three-way handshake
· Handwaving
· Two-way handshake
The TCP Three-Way Handshake is a procedure in which two devices (for example, a client and a server) exchange a sequence of three TCP segments in order to establish a trustworthy connection prior to the beginning of the real data transfer. This happens before the actual data transmission starts.
Answers
· presentation layer
· application layer
· session layer
· data layer
It is the responsibility of this component to ensure that the data transmitted and received by applications is displayed in a way that is both legible and useable. It handles things like character encoding, data compression, and encryption and decryption, and it makes sure that the data at the application layer is turned into a form that the program can comprehend.
The Presentation Layer is responsible for managing these responsibilities, which enables it to promote the interoperability of programs running on various platforms and maybe using different data formats.
Answers
· RST
· SYN
· FIN
· PSH
When a piece of hardware transmits a TCP segment with the RST flag set, it communicates two things: it wishes to promptly terminate the connection, and it communicates that there is an error situation. This flag is often set if a device has an issue that prohibits it from continuing the conversation or whenever it gets data that is either unexpected or malformed.
In a nutshell, the RST flag in TCP is a mechanism to reset and terminate a connection forcibly in the event that an error has occurred or there is no way to recover from a challenging circumstance.
Answers
· application
· network
· transport
· data-link
HTTP is the protocol that allows web browsers and web servers to communicate with one another, which in turn makes it easier to send hypertext (formatted text, pictures, videos, and so on) over the Internet. It functions at the application layer since it is responsible for defining the manner in which apps (web browsers and web servers) communicate and share information with one another.
The File Transfer Protocol (FTP), the Simple Mail Transfer Protocol (SMTP), and the Domain Name System (DNS) are a few further examples of protocols that belong to the Application Layer. The connection between programs that are operating on separate devices that are linked to a network is governed by these protocols, which establish the rules for such communication.
Answers
· 10.1.1.150.80
· 10.1.1.150.21
· 10.1.1.150:21
· 10.1.1.150:80
Answers
· Sequence number
· Acknowledgement number
· Checksum
· Urgent pointer
When data is broken up into segments for transmission, either because an Ethernet frame can only hold so much information or for some other reason, the sequence numbers play an important role in ensuring that the segments are sent in the right order. Before transmitting the data to the higher-layer application, the receiving TCP stack utilizes these sequence numbers to appropriately organize and reassemble the segments in preparation for doing so.
Answers
· seven
· five
· six
· eight
Answers
· reserved
· ephemeral
· registered
· system
In most cases, the number of ephemeral ports is selected from the range of 49152 to 65535. When a client first establishes a connection to a server, the operating system will designate a free ephemeral port for the client to make use of throughout the course of that particular session. This enables a number of client apps to concurrently make connections to a number of different servers without causing any issues.
Answers
· Random
· Prioritized
· Largest to smallest
· Sequential
The sequence numbers included inside the TCP header are absolutely necessary in order to keep the segments in the right order. Before providing the data to the higher-layer application, the receiving TCP stack utilizes these sequence numbers to reassemble the segments in the appropriate order so that they may be processed.
Therefore, the sequence of transmitting and receiving TCP segments is normally retained, which guarantees that the data is sent to the receiving application in the same order that it was transmitted by the program that was sending it.
Answers
· Socket address
· Demultiplexing
· Multiplexing
· File Transfer
Each communication endpoint (such as an application or service) is identified within the context of the transport layer by a combination of an IP address and a port number. This may be done in a variety of ways. The port number plays an important role in ensuring that the incoming data is sent to the correct receiving service on the destination node.
For instance, the port number in TCP (Transmission Control Protocol) and UDP (User Datagram Protocol) is a 16-bit field that has the potential value of anywhere between 0 and 65535. Port numbers that are well-known are set aside for certain services (for example, port 80 is used for HTTP, and port 21 is used for FTP), whereas port numbers that are dynamically issued or private are used for other reasons. Because of this, individual nodes are able to route traffic to the appropriate application or service depending on the port number.
33. Which field in a Transmission Control Protocol (TCP) header is chosen from ephemeral ports?
Answers
· Acknowledgement number
· Source port
· Sequence number
· Destination port
When a client begins the process of establishing an outbound connection to a server, the operating system of the client will normally choose an accessible ephemeral port to act as the connection's source port. The number range used to choose ephemeral ports is typically between 49152 and 65535. The TCP header contains information that helps uniquely identify the communication endpoints for the TCP connection. This information is comprised of the source port as well as the destination port.
In a nutshell, the Source Port field in the TCP header is determined by selecting a port from a pool of ephemeral ports when client programs want to establish outbound connections.
Answers
· SYN_RECEIVED
· LISTEN
· SYN_SENT
· ESTABLISHED
Explanation: When a Transmission Control Protocol (TCP) connection is functioning properly and both parties are able to communicate data to one another, the TCP socket state is said to be "ESTABLISHED." In the TCP state diagram, the word "ESTABLISHED" indicates that the TCP connection has been successfully established. At this point, data may be sent in both directions between the devices that are interacting with one another.
The client and the server are both actively conversing with one another and exchanging data packets across the connection that has been established at this point. Once the TCP connection's three-way handshake has been completed and both ends of the connection have recognized that it has been established, the connection will enter this regular operating state.
35. If the checksum doesn't compute for a packet sent at the Internet Protocol (IP) level, what will happen to the data?
Answers
· The data will be discarded
· The data will be sent back to the sending node with an error.
· The data will be resent
· It will be sent, but may be out of order.
When an IP packet is received by a device, the device recalculates the checksum based on the content of the packet and then compares this newly calculated checksum to the checksum value that is given in the packet header. It is an indication that the packet may have been corrupted while it was being sent if the checksum that was computed does not match the one that was included in the header.
When this occurs, the device that is doing the receiving makes the assumption that the packet is unstable or has been tampered with and decides to throw it away. This prevents the delivery of data that has been damaged or might possibly be harmful, hence preserving the integrity of data transmission inside IP networks.
Answers
· FIN
· RST
· SYN
· PSH
The Urgent Pointer element indicates the location of the conclusion of the urgent data included inside the TCP segment. It is common practice to make use of the URG flag in combination with the Urgent Pointer when communicating to the receiving application that certain data contained within the segment demands urgent attention or must be given priority processing.
Answers
· payload
· footer
· header
· flags
This application layer data must be segmented, encapsulated, and then transported to its final destination via the transport layer. The application's real data, known as the payload, is located in the data part of the transport layer segment. This component of the segment is responsible for sending the data over the network.
Answers
· FINISHED
· CLOSE_WAIT
· FIN_WAIT
· CLOSED
During the process of closing a TCP connection, the connection will cycle through a number of different states. These states include FIN_WAIT_1, FIN_WAIT_2, TIME_WAIT, and others. When both ends of the connection have accepted that the connection has been severed, it will eventually transition into the CLOSED state. At this point, the socket will be made available for other uses.
In a nutshell, the CLOSED state in TCP denotes that the socket has been closed and is no longer accessible for any further transmission.
Answers
· Acknowledgements
· Approvals
· Recognition
· Verifiers
The sender is responsible for sending data segments to the receiver in a connection-oriented communication, and the receiver is responsible for sending acknowledgments back to the sender to certify that they have successfully received the data. In the event that a data segment is either misplaced or fails to be correctly received, the sender will not get the anticipated acknowledgment, and it will proceed to retransmit the data.
This continuous back-and-forth of acknowledgments serves to assure the transmission of data in a dependable and sequential manner. In the event that a segment is not properly sent, the sender will continue to try sending it until the recipient indicates that they have successfully received it. In connection-oriented protocols, the use of this technique helps to avoid the loss of data and assures that the information that is transferred is complete and accurate.
Answers
· high five
· two-way handshake
· three-way handshake
· four-way handshake
41. What port does the File Transfer Protocol (FTP) typically listen on?
Answers
· 80
· 21
· 25
· 443
The transport of data via FTP happens over a different channel, and extra ports are used for data connections depending on whether the mode is active or passive. On the other hand, port 21 is always used for the connection that controls the system and is where instructions and replies are traded.
You have 3 networks (A, B, and C) and 2 routers (Y and Z).
Network A has an address space of 10.1.1.0/24 and is connected to router Y, using the interface 10.1.1.1.
Network B has an address space of 192.168.1.0/24 and is connected to Router Y, using the interface 192.168.1.254. Network B is also connected with router Z, using the interface of 192.168.1.1.
Network C has an address space of 172.16.1.0/24 and is connected to router Z, using the interface 172.16.1.1. The diagram below represents these connections and interfaces.
Answers
· Not present
· Network C
· Network A
· Network B
Answers
· To obtain Router Y’s MAC address
· To verify the internet connection
· To obtain Computer 2 MAC address
· To calculate the TTL
Explanation: When a computer, which we will refer to as Computer 1, sends a message using the Address Resolution Protocol (ARP) with the target media access control (MAC) address of FF:FF:FF:FF:FF:FF, that computer is broadcasting an ARP request to all of the nodes that are connected to the network. This particular kind of ARP request is referred to as a "broadcast ARP request."
This broadcast ARP request has been sent out with the intention of locating the node on the network whose MAC address corresponds to its IP address and learning that information. To put it another way, Computer 1 is looking for the MAC address that corresponds to a certain IP address, so it sends out a broadcast ARP request to all of the nodes in the network, requesting the node that has the IP address in question to reply with its MAC address.
The resolution of IP addresses to MAC addresses is a process that is often used in local area networks (LANs). This helps to ensure that devices on the same network segment are able to interact with one another.
44. Which layer constructs the IP datagram?
Answers
· Physical Layer
· Application layer
· Network layer
· Data layer
Explanation: The "Network Layer" is the layer that is responsible for constructing the IP datagram. Within the framework of the Internet Protocol Suite, which is more often referred to as TCP/IP, the Network Layer is in charge of the addressing and routing of packets (or datagrams) between devices that are connected to various networks.
The Internet Protocol (IP) works at the Network Layer and is in charge of encapsulating data from higher layers into IP datagrams. This function is performed at the Network Layer. As the fundamental unit enabling the transmission of data over IP networks, the IP datagram contains not only the IP addresses of the sender and receiver but also various forms of control information.
In conclusion, the Network Layer is responsible for the construction of the IP datagram, which makes the transmission of data between devices in a network more simpler.
45. What information is in the data payload of the Ethernet frame?
Answers
· IP datagram
· network interface
· ART message
· Handshake
In the event that an Ethernet frame is transporting an IP packet, for instance, the data payload would consist of the IP packet in its entirety, including both its header and its payload. Likewise, if an Ethernet frame were conveying a TCP or UDP segment, the data payload would comprise the whole of the segment, including both the headers and the payload for the appropriate protocol.
The Ethernet header, which contains the source and destination MAC addresses, an EtherType field, and occasionally a VLAN tag, is the component that makes up the structure of an Ethernet frame. After the header comes the data payload, which may have a variety of different contents depending on the protocol that is being conveyed inside the Ethernet frame.
Answers
· Computer 2’s MAC address
· Router Y’s MAC address
· Computer 1’s MAC address
· Router Z’s MAC address
In the header of an Ethernet frame, you'll find the MAC addresses for both the source and the destination. The MAC address of the device that is providing the data, in this case Router Y, is known as the source MAC address. The MAC address of the device that is receiving the data, Router Z, is known as the destination MAC address.
When the Ethernet frame finally reaches Router Z, the network interface card (NIC) of Router Z will verify the destination MAC address to determine whether or not the frame is meant for it. This will allow Router Z to determine whether or not the frame is intended for it. After it has been decapsulated, the IP packet that is included inside the Ethernet frame will next be handled by the networking stack that is located on Router Z.
Answers
· Sends an ARP broadcast message
· Sends back the packages to router Y for confirmation
· Calculates a checksum and compares this checksum with the one in the Ethernet frame header
· Strips away the Ethernet frame, leaving the IP datagram. Performs a checksum calculation against the entire datagram
Answers
· 0
· 61
· 65
· 63
Assuming the packet goes via Router Z and another router in Network B on its way to Computer 2 on Network C, the TTL value will be reduced by 2 because of this.
Answers
· Source Port: 80
Destination Port: 5000
Sequence Number: 1
Acknowledgment Number: 2
· Source Port: 5000
Destination Port: 80
Sequence Number: 1
Acknowledgment Number: 2
· Source Port: 8081
Destination Port: 50
Sequence Number: 4
Acknowledgment Number: 1
· Source Port: 80
Destination Port: 5000
Sequence Number: 1
Acknowledgment Number: 1
Explanation: This is the fundamental data that must be provided for the first TCP segment. Additional fields such as Sequence Number, Acknowledgment Number, Data Offset, Flags (such as the SYN flag for the first connection), Window Size, Checksum, and Urgent Pointer would be included in a genuine TCP segment. These fields would be included in a legitimate TCP segment. The values for these variables would be determined by the particulars of the TCP protocol as well as the communication that is currently taking place.
50. Computer 1 on network A, with IP address of 10.1.1.10, wants to send a packet to Computer 2, with IP address of 172.16.1.64. Which of the following has the correct IP datagram information for the fields: Version, minimum Header Length, Source IP, and Destination IP?
Answers
· Version: 5
Header Length: 16
Source IP Address: 171.1.1.1.
Destination IP address: 172.16.1.0/24.
· Version: 6
Header Length: 20
Source IP Address: 8a:1a:2b:3c:4d:5f
Destination IP address: 2a:2b:3c:4d:8f
· Version: 4
Header Length: 20
Source IP Address: 10.1.1.10
Destination IP address: 172.16.1.64
· Version: 4
Header Length: 32
Source IP Address: 10.1.1.1
Destination IP address: 172.16.1.1
Answers
· network identification
· ethernet port
· router velocity
· cable plug
Explanation: When we talk about RJ45, we are talking to a particular kind of connection that is often used for Ethernet networking. RJ45 is an abbreviation that stands for "Registered Jack 45," and it refers to a common connection that is used often in the process of joining network cables, most notably in Ethernet networks.
The RJ45 connection is often used with twisted-pair cables and consists of eight individual pins. It is used to terminate the ends of Ethernet cables, making it possible for various pieces of networking equipment, including computers, routers, switches, and others, to be linked to a network.
Ethernet networking often makes use of Category 5 (Cat5), Category 5e (Cat5e), Category 6 (Cat6), and Category 6a (Cat6a) connections; hence, RJ45 connectors are frequently used with these types of cables. A modular connection known as an RJ45 connector may be crimped onto the end of a network cable to provide a standardized interface for linking devices in a local area network (LAN). This kind of connector is known as an RJ45 connector.
Shuffle Q/A 1
Answers
· Network C
· Network B
· Not present
· Network A
Since this is the case, Computer 2 is also connected to Network A. Since the devices are part of the same network segment, they are able to engage in direct communication with one another inside the same subnet without the intervention of any routing protocols.
Answers
· Port number
· MAC address
· TTL value
· Destination MAC address
In this example, the gateway is often a router, which performs the function of acting as an intermediate by routing packets across several networks. It is necessary for Computer 1 to ascertain the MAC address of the interface on the router that is linked to the local network (the default gateway). This is accomplished by examining its ARP table, which contains a mapping of IP addresses to MAC addresses.
Computer 1 will submit an ARP request to the local network in the event that the MAC address corresponding to the gateway's IP address is not already stored in the ARP table. The request will inquire about the MAC address that is associated with the gateway's IP address. As soon as it has the ARP reply including the MAC address, it is able to encapsulate the packet with the proper destination MAC address and then transmit it to the gateway so that it may be routed further.
54. Which layer constructs the Ethernet frame?
Answers
· Data link layer
· Application layer
· Physical Layer
· Transport layer
Explanation: The "Data Link Layer," more particularly the "Ethernet sublayer," is the layer that is responsible for the construction of the Ethernet frame. The Data Link Layer is subdivided into two parts under the OSI model; these parts are referred to as the Logical Link Control (LLC) sublayer and the Media Access Control (MAC) sublayer respectively.
The framing of data for transmission across the physical network media is the responsibility of Ethernet, which works at the Media Access Control (MAC) sublayer of the Data Link Layer. The source and destination MAC addresses, as well as data, are included inside an Ethernet frame alongside an EtherType field.
In response to your inquiry, the Ethernet frame is built at the Data Link Layer, more precisely at the Media Access Control (MAC) sublayer that resides inside that layer.
55. Computer 1 on network C, with IP address of 172.16.1.57, wants to send a packet to Computer 2, with IP address of 172.16.1.133. If the TTL value was set to 64 at the beginning, what is the value of the TTL once it reaches its destination?
Answers
· 64
· 0
· 61
· 65
Explanation: When a packet is sent from Computer 1 to Computer 2 on Network C, the Time-to-Live (TTL) value does not change because, under the assumption that the computers are part of the same subnet or local network (there are no routers involved), the value does not change. In most cases, the TTL will decrease by one with each subsequent router hop.
When it reaches its destination, Computer 2, the TTL value will still be 64 if the computers are on the same subnet and there are no routers in the path. Because the packet does not go via any routers, the TTL field does not be decremented in this scenario. The TTL is normally dropped by one at each router hop to guarantee that the packet has a limited lifetime. This is done because the TTL is mainly used for the purpose of preventing packets from recirculating endlessly inside the network.
56. Computer 1 on network B, with IP address of 192.168.1.233, wants to send a packet to Computer 2, with IP address of 172.16.1.133. Which of the following has the correct IP datagram information for the fields: Version, minimum Header Length, Source IP, and Destination IP?
Answers
· Version: 4
Header Length: 20
Source IP Address: 192.168.233
Destination IP address: 172.16.1.133
· Version: 5
Header Length: 16
Source IP Address: 10.1.1.0/24.
Destination IP address: 172.16.1.0/24.
· Version: 4
Header Length: 32
Source IP Address: 10.1.1.1
Destination IP address:172.16.1.1
· Version: 6
Header Length: 20
Source IP Address: 8a:1a:2b:3c:4d:5f
Destination IP address: 2a:2b:3c:4d:8f
57. The Cat6 cable is part of the ______ layer.
Answers
· Transport
· Application
· Physical
· Network
Explanation: In the OSI model, the "Physical Layer" includes the Cat6 cable as one of its components. The Physical Layer is the lowest layer in the OSI (Open Systems Interconnection) paradigm. It is in charge of the transmission and receipt of raw data bits across a physical media, such as cables, connectors, and switches, and it is the layer that is responsible for the Open Systems Interconnection.
Ethernet networks often make use of twisted pair cables of the Cat6 (Category 6) kind. Cat6 stands for "Category 6." It offers a larger bandwidth as well as improved performance in comparison to earlier category standards such as Cat5 or Cat5e. The properties of the physical connection, such as the kind of cable that is used, the connections, signaling, and the physical architecture of the network, are all defined by the Physical Layer of the OSI model.
58. What information is computer 1 looking at in the ARP table on Router Y?
Answers
· Destination MAC address
· Port number
· TTL value
· MAC address
Explanation: When Computer 1 queries the Address Resolution Protocol (ARP) database that is stored on Router Y, it is seeking for a mapping that corresponds MAC addresses to IP addresses. To be more specific, Computer 1 is looking for the Media Access Control address, also known as MAC address, that corresponds to the IP address of its default gateway or the interface of the router that is linked to its local network.
In the context of ARP, the table generally comprises entries that connect IP addresses with the MAC addresses that are associated with them. The ARP table provides the router with the information it needs to correctly route data packets to the network's subsequent hops. When Computer 1 wishes to connect with devices that are not part of its local network, it sends the packets to the default gateway, which is Router Y. In order to encapsulate the packets appropriately so that they may be sent on the local network, Computer 1 requires the MAC address of the router's interface.
In conclusion, Computer 1 is now consulting the ARP table that is stored on Router Y in order to locate the MAC address of the router's interface that acts as the default gateway for traffic coming from outside the local area network.
59. Computer 1 on network C, with IP address of 172.16.1.57, wants to send a packet to Computer 2, with IP address of 192.168.1.14. Taking in consideration that computer 1 is sending a request to a web server on computer 2, listening on port 80, and the source port on computer 1 is 5000, which of the following contains the correct information for the fourth TCP segment of data?
Answers
· Source Port: 5000
Destination Port: 80
Sequence Number: 1
Acknowledgment Number: 2
· Source Port: 8081
Destination Port: 50
Sequence Number: 4
Acknowledgment Number: 1
· Source Port: 5000
Destination Port: 80
Sequence Number: 4
Acknowledgment Number: 5
· Source Port: 80
Destination Port: 5000
Sequence Number: 1
Acknowledgment Number: 1
60. When constructing the Ethernet datagram to send the packet from Router Z to Computer 2 which is on Network C, what information needs to be in the destination MAC address?
Answers
· Computer 2’s MAC address
· Router Y’s MAC address
· Computer 1’s MAC address
· No MAC address is needed
Explanation: When an Ethernet datagram is being constructed to transmit a packet from Router Z to Computer 2, which is on Network C, the destination MAC address must be the MAC address of the network interface card (NIC) of the next hop or the ultimate destination. This is because the MAC address of the final destination is used to determine if the packet was successfully delivered.
Assuming that the packet is being transmitted from Router Z to Computer 2, Router Z has to know the media access control (MAC) address of either Computer 2 or the next router along the way to Computer 2.
The MAC address of the network interface card (NIC) on the device that is either the ultimate destination (Computer 2) or the next hop router on the way toward Computer 2 will be the destination MAC address that is included in the Ethernet frame. Before delivering the packet, this MAC address is resolved using the Address Resolution Protocol, which helps establish its location. If Router Z already has the MAC address, it will make use of that information; otherwise, it will use ARP in order to locate it.
61. Computer 1 on Network A sends a packet to Computer 2 on Network C. What's the last step that Router Z does after receiving the Ethernet frame?
Answers
· Sends back the packages to router Y for confirmation
· Decrements the TTL by 1, calculates a new checksum, and makes a new IP datagram. This new IP datagram is again encapsulated on a new Ethernet frame.
· Strips away the Ethernet frame, leaving the IP datagram. Performs a checksum calculation against the entire datagram
· Calculates a checksum and compares this checksum with the one in the Ethernet frame header
62. Computer 1 on network A, with IP address of 10.1.1.8, wants to send a packet to Computer 2, with IP address of 172.16.1.64. If the TTL value was set to 64 at the beginning, what is the value of the TTL once it reaches its destination?
Answers
· 65
· 60
· 0
· 62
Explanation: Assuming that the packet stays on the same local network during its journey from Computer 1 to Computer 2, the Time-to-Live (TTL) number will not change. This is because there will be no routers involved in this scenario. The TTL value is reduced by one at each router hop; however, if the devices are on the same subnet, there are no intervening routers; hence, the TTL value is unaffected and stays unchanged.
Because of this, the TTL value will not change when it reaches its destination (Computer 2) on the same local network (Network A) if Computer 1 sends a packet to Computer 2 on that network. At each router hop, the TTL value is reduced, which serves the purpose of preventing data packets from traveling around the network in an unending loop. Since there are no routers involved in this scenario, the TTL does not change.
63. The ________ layer is responsible for sending ones and zeros through a process called modulation from Computer 1 to Computer 2.
Answers
· Transport
· Physical
· Network
· Application
Explanation: The "Physical Layer" is in charge of the transmission of ones and zeros from Computer 1 to Computer 2 using a method known as modulation. The transmission and receiving of raw binary data via a physical media is the responsibility of the Physical Layer, which is the lowest layer in the OSI (Open Systems Interconnection) paradigm.
The act of converting digital data into analog signals so that it may be sent via a physical communication channel is referred to as modulation. This layer is concerned with the actual physical connection between devices, including the properties of the transmission medium, which might include things like cables, connections, and the modulation methods that are used for signaling.
In the context of computer networking, the Physical Layer is the layer that is responsible for ensuring that the bits created by higher layers are correctly sent across the physical channel and are received properly by the device that is doing the receiving.
64. If it’s a TCP connection, which is the first segment that computer 1 needs to build?
Answers
· IP datagram
· handshake
· TCP segment
· Ethernet frame
65. What information is in the payload section of the TCP segments?
Answers
· The application layer data
· ART Table
· The MAC address of Computer 1
· Handshake
Explanation: The actual data that is being sent between the sender and the receiver is included inside the payload part of TCP (Transmission Control Protocol) segments. When discussing TCP, the payload is often referred to as the "data" or the "application data." This is the data that the application layer intends to convey, and it is cloaked in the TCP segment for protection.
Use the following scenario to answer the 10 questions below:
You have 3 networks (A, B, and C) and 2 routers (Y and Z).
Network A has an address space of 10.1.1.0/24 and is connected to router Y, using the interface 10.1.1.1.
Network B has an address space of 192.168.1.0/24 and is connected to Router Y, using the interface 192.168.1.254. Network B is also connected with router Z, using the interface of 192.168.1.1.
Network C has an address space of 172.16.1.0/24 and is connected to router Z, using the interface 172.16.1.1. The diagram below represents these connections and interfaces.
66. Computer 1 on network A, with IP address of 10.1.1.205, wants to send a packet to Computer 2, with IP address of 172.16.1.57. On which network is computer 2?
Answers
· Network A
· Network B
· Local network
· Network C