Week 2 – The Network Layer

 

1. Please select all of the valid IP addresses. Check all that apply.

Answers

·        8.8.8.8

·        123.456.123.456

·        192.168.1.1

·        257.70.312.49

Explanation: These are examples of valid IP addresses in both IPv4 and IPv6 formats. It is important to keep in mind that legitimate IP addresses must correspond to the standards set for either IPv4 or IPv6, as well as particular rules and ranges that govern them.

2. How many IP addresses does a class C network have?

Answers

·        16,777,216 addresses

·        256 addresses

·        65,536 addresses

·        1 address

Explanation: A certain range of Internet Protocol (IP) addresses is used by a Class C network. A Class C network in the context of IPv4 addressing contains 256 addresses, however the addresses that may actually be used for hosts are often just 254. This is due to the fact that the first and final addresses in the range are set aside specifically for the purposes of network identification and broadcast, respectively.

A Class C network may have any IP address in the range 192.0.0.0 to 223.255.255.255 as its domain name. A Class C network has a subnet mask of 255.255.255.0, which indicates that the first three octets describe the network and the final octet is free for host addresses to be assigned to it.

Therefore, a Class C network has the potential to support 28 IP addresses, or 256, but two of those addresses are set aside for the purposes of network identification and broadcasting. This leaves 254 addresses that may be used by hosts that are part of that network.

3. Which IP address class has the first two octets reserved for the network ID and the last two octets for the host ID?

Answers

·        Class B

·        Class A

·        Class E

·        Class C addresses

Explanation: Class B is the IP address class that has the first two octets designated for the network ID and the final two octets reserved for the host ID. Both of these octets are located at the end of the address. The network part of a Class B IP address takes up the first 16 bits (two octets), while the host address portion of the address takes up the remaining 16 bits (two octets) of the Class B IP address.

4. The ____ is used to indicate that the datagram is allowed to be fragmented or to indicate that the datagram has already been fragmented.

Answers

·        service type field

·        fragmentation offset field

·        total length field

·        flag field

Explanation: The "Fragmentation" field in the IP header is used to either signal that the datagram has already been fragmented or that it may be fragmented in the future. It may also be used to indicate that the datagram may be fragmented in the future. This section of the IP (Internet Protocol) header is responsible for managing the transmission of data across networks that have varying Maximum Transmission Unit (MTU) sizes. The IP header is a component of the Internet Protocol. The Fragmentation field includes flags such as "Don't Fragment (DF)" and "More Fragments (MF)" to control the fragmentation process.

5. The IP address assigned to a device would depend on the _______ it is connected.

Answers

·        network

·        ARP

·        MAC addresses

·        IP datagram

Explanation: The IP address that is given to a piece of hardware is determined by the network to which it is attached. IP addresses are used to uniquely identify devices that are part of a network. These addresses are allocated depending on the architecture of the network. Each device connected to a network must have a unique IP address to facilitate communication and data exchange within that network. In most cases, network administrators or Dynamic Host Configuration Protocol (DHCP) servers are responsible for managing the assignment of IP addresses. However, in the event of dynamic IP address allocation, this responsibility may shift.

6. What does CIDR stand for?

Answers

·        Classful Identification Routing

·        Class Interconnect Destination Routing

·        Classful Interlink-Destination Routing

·        Classless Inter-Domain Routing

Explanation: Classless Inter-Domain Routing is what CIDR, or just CIDR, stands for. The old approach, which is based on classes (Class A, Class B, and Class C networks), is less flexible than the CIDR technique, which is used to assign and describe IP addresses and their routing in a manner that is more adaptable.

CIDR makes it possible to aggregate IP addresses into blocks, doing away with the need for strictly delineated class boundaries. It is denoted by an IP address, which is then followed by a forward slash and a decimal number. This number represents the number of bits that are used for the network component. For example, "192.168.1.0/24" denotes a CIDR notation where the first 24 bits represent the network, and the remaining 8 bits are available for host addresses.

Through helping to optimize the distribution of IP addresses and reducing the size of routing tables, CIDR contributes to the improvement of the effectiveness of Internet routing.

7. Which of the following is a correct form of CIDR notation?

Answers

·        192.168.1.0 + 255.255.255.0

·        192.168.1.0/24

·        192.168.1.0:24

·        192.168.1.0\24

Explanation: The right way to write CIDR, which stands for Classless Inter-Domain Routing, is an IP address followed by a forward slash and a decimal number that indicates the number of bits that are utilized for the network component.

8. How many octets does a subnet mask have?

Answers

·        4

·        1

·        3

·        2

Explanation: A subnet mask is made up of 32 bits and is often shown in dotted-decimal format so that it can be read by humans. Each set of 8 bits in the binary representation of the subnet mask is represented as a dotted-decimal octet, which means that each octet in the dotted-decimal notation has 8 bits.

As a result, a subnet mask is comprised of four octets. When expressed in decimal form, an octet looks like a sequence of four integers separated by dots (for example, 255.255.255.0), since each octet is equivalent to one byte.

Within a particular network, the subnet mask is an extremely important component in the process of determining the network and host components of an IP address. The number of consecutive "1" bits in the subnet mask indicates the length of the network prefix, determining the size of the network and the number of available host addresses.

9. Consider the following scenario:

Your IP address is 192.168.8.34, and your subnet mask is 255.255.0.0. What part of the subnet mask represents the subnet ID?

Answers

·        The last two octets of the subnet mask, 0.0

·        The first two octets of the subnet mask, 255.255

·        192.168.0.254

·        255.255.0.1

10. How many possible host IDs do you always lose per network?

Answers

·        2

·        12

·        4

·        8

11. Which of the following are types of Interior Gateway Protocols? (Select all that apply)

Answers

·        Link State Routing Protocols

·        Distance-Vector Protocols.

·        Hypertext Transfer Protocol

·        Transmission Control Protocol

Explanation: These protocols were developed specifically for the purpose of routing inside an autonomous system (AS), and they are used by routers that are part of the same network to communicate routing information with one another. In comparison, Exterior Gateway Protocols (EGPs), which are used for the process of routing data between various autonomous systems, are described below.

12. Who is permitted to use non-routable address space?

Answers

·        It’s for testing purposes only

·        The IANA

·        The IETF

·        Anyone

Explanation: Address space that is not meant to be routable on the public Internet is referred to as non-routable address space. This address space is sometimes referred to as private IP address space. It is reserved for usage only inside private networks. RFC 1918 details the procedures for using address space that is not routable.

13. A typical routing table may contain which of the following? Check all that apply.

Answers

·        Total Hops

·        TTL

·        Destination Network

·        Destination address

14. What is the difference between Interior Gateway Protocols and Exterior Gateway Protocols?

Answers

·        Interior gateway protocols share information with public networks. Exterior gateway protocols are used for private networks.

·        Interior Gateway Protocols share information within a single autonomous system. Exterior Gateway Protocols are used for the exchange of information between multiple autonomous systems.

·        Interior gateway protocols share information with multiple autonomous systems. Exterior Gateway Protocols are used for the exchange of information between independent autonomous systems.

·        There is no difference between them.

Explanation: IGPs are used for routing inside a single organization or network (within the borders of an AS), but EGPs are used for routing across several organizations or networks (across the boundaries of ASes). In conclusion, IGPs are used for intra-organizational routing, whilst EGPs are utilized inter-organizational routing. Each component fulfills a unique function that contributes to the overarching architecture of the Internet and other large-scale networks.

15. Which of the following are non-routable IP addresses? (Select all that apply)

Answers

·        172.16.0.0/12

·        192.168.0.0/16

·        9.0.0.0

·        10.0.0.0/8

 

16. No matter where a device is used, what address will stay the same regardless of the network it is attached to?

Answers

·        Physical, or MAC, address

·        Dynamic IP address

·        Static IP address

·        EIN serial

Explanation: The MAC address, also known as the Media Access Control address, is the address that remains consistent for a device independent of the network to which it is connected. A network interface card (NIC) of a device, such as a computer, smartphone, or networked printer, is given a unique identifier called a MAC address. This address is used to identify the device.

In contrast to IP addresses, which might shift depending on the network setup and location, the media access control (MAC) address will never change for a given network interface no matter how long the device in question is in use. It is hardcoded into the NIC by the manufacturer and serves as a globally unique identifier for that particular hardware.

In the OSI model, the media access control address (MAC address) is utilized at the data connection layer. This address is critical to the operation of Ethernet as well as other networking protocols. It is normally not utilized for routing traffic across various networks since it is only intended for usage inside a network segment for the purpose of local communication.

 

17. There are ____ octets in an IP address.

Answers

·        16

·        8

·        2

·        4

Explanation: An Internet Protocol address is comprised of a total of four octets. An IPv4 address is made up of a total of 32 bits, each of which is represented by an octet of the address. The IPv4 address is usually expressed in dotted-decimal notation, where each octet is separated by a dot. An IPv4 address such as "192.168.1.1" is an example of a string that has four octets. It is possible for each octet to have a value anywhere from 0 to 255, inclusive.

 

18. What is the process of taking a single IP datagram and splitting it up into several smaller datagrams called?

Answers

·        Fragmentation

·        Clustering

·        NAT firewall

·        Load balancing

Explanation: The act of taking a single IP datagram and slicing it up into multiple other datagrams of a more manageable size is referred to as fragmentation. The process of fragmentation happens when a big IP datagram that is greater than the Maximum Transmission Unit (MTU) of a network segment has to be transferred over that segment. The MTU is the maximum amount of data that may be sent across a network segment at one time.

The initial datagram is broken up into a number of smaller pieces, each of which may be sent across the network without exceeding its maximum transmission unit (MTU). These fragments can be transmitted independently to reach the destination, where they are reassembled to reconstruct the original datagram. The Internet Protocol (IP) includes specifications for the fragmentation and reassembly procedures in order to permit the transfer of data across networks that have varied maximum transmission unit sizes.

 

19. In a Class A address, the possible values for the first octet are:

Answers

·        0 through 127

·        255 through 420

·        0 through 255

·        128 through 199

 

20. What does ARP stand for?

Answers

·        Anonymous Resource Protocol

·        Augmented Resolution Picture

·        Address Resolution Protocol

·        Aggressive Resource Protection

Explanation: The abbreviation for "Address Resolution Protocol" is "ARP." It's used for mapping a network layer address (such as an IP address) to a physical (MAC) address in a local network. In a nutshell, it assists the various devices on a network in locating one another.

 

21. What does CIDR stand for?

Answers

·        Costless Inter-Data Routing

·        Classless Inter-Domain Routing

·        Clear Inter-Developer Relations

·        Classic Intra-Demo Ratings

 

22. A router is performing basic routing functions. What is the first step in the transmission of a packet?

Answers

·        The router examines the destination IP of this packet.

·        Sent an ARP response.

·        Check the routing table.

·        A router receives a packet of data.

Explanation: The data packet is taken in by the router. -The router looks at the IP address of the destination. -The router will send the packet on its way. Learn more about what the community thinks and get a badge.

 

23. Link state routing protocols are newer and they require…

Answers

·        Modern encryption standards

·        Manual updating

·        Less memory and less processing power

·        More memory and more processing power

24. What organization helps manage IP address allocation and autonomous system number allocation?

Answers

·        ICANN

·        INNA

·        IANA

·        IBM

Explanation: The Internet Assigned Numbers Authority (IANA) is a standards organization that manages worldwide IP address allocation, number allocation for autonomous systems, root zone management in the Domain Name System (DNS), media type management, and a variety of other symbologies and numbers connected to Internet Protocol.

25. What does RFC stand for?

Answers

·        Realtime Frame Check

·        Request For Comments

·        Redundant Frame Controller

·        Routing Frequency Control

Explanation: An Internet Engineering Task Force (IETF) Request for Comments (RFC) is a formal document that provides specifications and organizational comments regarding issues relevant to the internet and computer networking. These topics include things like routing, addressing, and transport technologies. RFCs are issued by the Internet Engineering Task Force (IETF).

Shuffle Q/A 1

26. What is eight bits of data called?

Answers

·        Octuplet

·        Figure eight

·        Octoploid

·        Octet

 

27. How many bits long is an IP address?

Answers

·        64 bits

·        32 bits

·        8 bits

·        256 bits

 

28. Which IP address is Class C?

Answers

·        128.42.39.72

·        172.38.14.72

·        224.24.45.69

·        192.37.48.98

29. When describing blocks of IP addresses, what does CIDR do?

Answers

·        Interpolates data across multiple servers

·        Calls back to the source router for confirmation

·        Uses subnet masks to demarcate networks.

·        Encrypts the header data

Explanation: Classless Inter-Domain Routing, often known as CIDR, is a protocol that gives network routers the ability to route data packets to the appropriate device depending on the subnet that is given. Instead of classifying the IP address based on classes, routers retrieve the network and host address as specified by the CIDR suffix.

 

30. What protocol communicates data between routers representing the edges of autonomous systems?

Answers

·        Distance-vector

·        Link state

·        Interior gateway

·        Exterior gateway

Explanation: Border Gateway Protocol (BGP) is a standardized gateway protocol that exchanges routing information across autonomous systems (AS) on the Internet.

 

31. Which of the following IP address ranges have been defined as non-routable address space? Select all that apply.

Answers

·        192.168.0.0/16

·        172.16.0.0/12

·        255.255.255.0/1

·        10.0.0.0/8

 

32. In a datagram, what does the flag field indicate?

Answers

·        If a datagram should be scanned for viruses

·        If a datagram has degraded and become unusable

·        If a datagram is high or low priority

·        If a datagram is allowed to or has already been fragmented

Explanation: The flag fields, which are seen in Figure 4.35, reveal whether or not a datagram is a portion that has been broken off from a bigger whole. The MF (More Fragments) flag of the flag field is set to signal that the fragment is the last piece (the end piece) of the datagram. This is indicated by the fact that the flag has been set.

 

33. A router is performing basic routing functions. What is the second step in the transmission of a packet?

Answers

·        A router receives a packet of data.

·        The router examines the destination IP of this packet.

·        Check the routing table.

·        Sent an ARP response.

Explanation: When a packet is received by the router, the IP header of the packet is examined. The destination IP address is the most essential part of the packet since it informs the router where the data should ultimately be delivered.

 

34. Ranges of IP addresses anyone can use for their internal networks are known as ______.

Answers

·        MAC address

·        Non-routable address space

·        Subnet mask

·        IP address

Explanation: A router examines the destination IP address in a packet's header and determines the best path to forward the packet to its destination. Filtering: Routers have the ability to filter packets according to a wide variety of parameters, including the source IP address, the destination IP address, the protocol type, the port number, and many more.

 

35. Which of the following is a valid IP address?

Answers

·        598.36.789

·        126.396.659.100

·        128.42.64.78

·        A8:97:4F:6D:H6:0F

 

36. A single octet in an IP address represents what range of decimal numbers?

Answers

·        0-255

·        0-250

·        1-255

·        0-155

Explanation: In an Internet Protocol address, what range of decimal values does a single octet represent? All decimal integers from 0 to 255 may be represented by a single octet of data, which consists of eight bits.

 

37. A router is performing basic routing functions. What is the third step in the transmission of a packet?

Answers

·        The router looks up the destination network in its routing table.

·        The router forwards the packet.

·        The router examines the destination IP.

·        A router receives a packet of data.

Explanation: In the second step, the router looks in its routing table for the network that is the target; in the third stage, the router looks in its routing table for the network that is the destination of the IP address. The network layer is the name given to the third step of the transmission process for a packet. The network layer is also responsible for adding the source IP address as well as the destination IP address.

Shuffle Q/A 2

38. Generally, what are Class E IP addresses used for?

Answers

·        CIDR

·        Multicasting

·        Broadcasting

·        Testing

 

39. Why do entries in a local Address Resolution Protocol (ARP) table expire after a short amount of time?

Answers

·        To keep space in the table

·        It will use too much memory

·        It only needs to be used one time

·        To account for network changes

40. QoS services are protocols that allow routers to make decisions about which IP datagram may be more important than others. Under which IP header field would QoS details be found?

Answers

·        Total length field

·        Identification field

·        Service Type field

·        Fragmentation offset field

41. What is the purpose of an ARP response?

Answers

·        To improve authentication security

·        To prevent a flood of UDP packets

·        To let a broadcasting node know what is the MAC address to put into the destination hardware address field

·        To send an ACK message to the broadcasting computer

Explanation: ARP is required because the software address, also known as the IP address, of the host computer or computer that is connected to the network has to be converted into the hardware address, also known as the MAC address. A host would be unable to determine the hardware address of another host if it did not have access to the ARP protocol.

42. What is one main reason CIDR is helpful in modern networking?

Answers

·        CIDR increases network security with no additional resources

·        CIDR simplifies MAC address assignment

·        CIDR lowers the amount of power needed to run a server

·        CIDR allows for more arbitrary network sizes

Explanation: Send the data as promptly as possible. CIDR enables routers to more effectively arrange IP addresses into different subnets than was previously possible. A smaller network that is contained inside a larger network is referred to as a subnet. As an example, all of the electronic gadgets that are linked to a router are included in the same subnet and share the same IP address prefix.

43. Interior gateway protocols are used by routers in order to share information within a single…

Answers

·        subnet

·        autonomous system

·        collision domain

·        destination network

Explanation: A dynamic route update protocol that is utilized between routers that operate on TCP/IP hosts inside a single autonomous system is referred to as an internal gateway protocol, or IGP for short. The routers use this protocol to exchange information about IP routes.