9. IPv4 and Network Segmentation //

Question 1

refers to one device sending a message to one other device in one-to-one communications.

Answer 1

Unicast transmission

Question 2

has a destination IP address that is a unicast address which goes to a single recipient.

Answer 2

unicast packet

Question 3

source IP address can only be a?

Answer 3

can only be a unicast address, because the packet can only originate from a single source. This is regardless of whether the destination IP address is a unicast, broadcast, or multicast.

Question 4

What is the slash notion for?

Answer 4

It indicates how many bits long

Question 5

What is the IP Address destination for broadcast?

Answer 5

255.255.255.255

Question 6

refers to a device sending a message to all the devices on a network in one-to-all communications.

Answer 6

Broadcast transmission

Question 7

has a destination IP address with all ones (1s) in the host portion, or 32 one (1) bits.

Answer 7

A broadcast packet

Question 8

reduces traffic by allowing a host to send a single packet to a selected set of hosts that subscribe to the group.

Answer 8

Multicast transmission

Question 9

is a packet with a destination IP address that is a multicast address.

Answer 9

multicast packet

Question 10

What are the IPv4 reserved Multicast Range?

Answer 10

IPv4 has reserved the 224.0.0.0 to 239.255.255.255 addresses as a multicast range.

Question 11

Hosts that receive particular multicast packets are called?

Answer 11

multicast clients

Question 12

How multicast group is represented?

Answer 12

Each multicast group is represented by a single IPv4 multicast destination address. When an IPv4 host subscribes to a multicast group, the host processes packets addressed to this multicast address, and packets addressed to its uniquely allocated unicast address.

Question 13

Explain this:

Routing protocols such as OSPF use multicast transmissions. For example, routers enabled with OSPF communicate with each other using the reserved OSPF multicast address 224.0.0.5. Only devices enabled with OSPF will process these packets with 224.0.0.5 as the destination IPv4 address. All other devices will ignore these packets.

Answer 13

(How well did you understand it?)

Question 14

are addresses which are globally routed between internet service provider (ISP) routers.

Answer 14

Public IPv4 addresses

Question 15

addresses that are used by most organizations to assign IPv4 addresses to internal hosts.

Answer 15

private addresses

Question 16

When was world wide web introduced?

Answer 16

mid-1990s

Question 17

is a technical document that defines reserved IPv4 address ranges for use within private networks. It outlines the specific IP address ranges that can be used within private, isolated network environments.

Answer 17

RFC 1918, “Address Allocation for Private Internets”

Question 18

What are the three private addresses and its range?

Answer 18

a) 10.0.0.0/8 = 10.0.0.0 - 10.255.255.255
b) 172.16.0.0/12 = 172.16.0.0 - 172.31.255.255
c) 192.168.0.0/16 = 192.168.0.0 - 192.168.255.255

Question 19

used to translate between private IPv4 and public IPv4 addresses.

Answer 19

Network Address Translation (NAT)

Question 20

How NAT is done?

Answer 20

This is usually done on the router that connects the internal network to the ISP network. Private IPv4 addresses in the organization’s intranet will be translated to public IPv4 addresses before routing to the internet.
Packets with a private address must be filtered (discarded) or translated to a public address before forwarding the packet to an ISP.

Question 21

What is the loopback address?

Answer 21

127.0.0.0 /8 or 127.0.0.1 to 127.255.255.254

Question 22

How ping command is used?

Answer 22

the ping command is commonly used to test connections to other hosts. But you can also use the ping command to test if the IP configuration on your own device

Question 23

What is the Link Local Address?

Answer 23

169.254.0.0 /16 or 169.254.0.1 to 169.254.255.254

Question 24

Link Local Address are most commonly known as?

Answer 24

The Automatic Private IP Addressing (APIPA) addresses or self-assigned addresses.

Question 25

What is the use of the Automatic Private IP Addressing (APIPA) addresses or self-assigned addresses?

Answer 25

They are used by a Windows client to self-configure in the event that the client cannot obtain an IP addressing through other methods. Link-local addresses can be used in a peer-to-peer connection but are not commonly used for this purpose.

Question 26

Designed to support extremely large networks with more than 16 million host addresses.

Answer 26

Class A (0.0.0.0/8 to 127.0.0.0/8)
Class A used a fixed /8 prefix with the first octet to indicate the network address and the remaining three octets for host addresses (more than 16 million host addresses per network).

Question 27

Designed to support the needs of moderate to large size networks with up to approximately 65,000 host addresses.

Answer 27

Class B (128.0.0.0 /16 - 191.255.0.0 /16)
Class B used a fixed /16 prefix with the two high-order octets to indicate the network address and the remaining two octets for host addresses (more than 65,000 host addresses per network).

Question 28

Designed to support small networks with a maximum of 254 hosts.

Answer 28

Class C (192.0.0.0 /24 - 223.255.255.0 /24)
Class C used a fixed /24 prefix with the first three octets to indicate the network and the remaining octet for the host addresses (only 254 host addresses per network).

Question 29

For how many host is Class A?

Answer 29

16 million host addresses.

Question 30

For how many host is Class B?

Answer 30

65,000 host addresses.

Question 31

For how many host is Class C?

Answer 31

maximum of 254 hosts.

Question 32

Class D is what?

Answer 32

Class D multicast block consisting of 224.0.0.0 to 239.0.0.0

Question 33

Class E is what?

Answer 33

experimental address block consisting of 240.0.0.0 - 255.0.0.0.

Question 34

Both IPv4 and IPv6 addresses are managed by?

Answer 34

by the Internet Assigned Numbers Authority (IANA).

Question 35

The IANA manages and allocates blocks of IP addresses to the?

Answer 35

to the Regional Internet Registries (RIRs).

Question 36

What are the five RIRs?

Answer 36

• AfriNIC (African Network Information Centre) - Africa Region
• APNIC (Asia Pacific Network Information Centre) - Asia/Pacific Region
• ARIN (American Registry for Internet Numbers) - North America Region
• LACNIC (Regional Latin-American and Caribbean IP Address Registry) - Latin America and some Caribbean Islands
• RIPE NCC (Réseaux IP Européens Network Coordination Centre) - Europe, the Middle East, and Central Asia

Question 37

This is to locate other devices.

Answer 37

In an Ethernet LAN, devices use broadcasts and the Address Resolution Protocol (ARP)

Question 38

How ARP works?

Answer 38

ARP sends Layer 2 broadcasts to a known IPv4 address on the local network to discover the associated MAC address. Devices on Ethernet LANs also locate other devices using services. A host typically acquires its IPv4 address configuration using the Dynamic Host Configuration Protocol (DHCP) which sends broadcasts on the local network to locate a DHCP server.

Question 39

How ARP propagate broadcasts?

Answer 39

Switches propagate broadcasts out all interfaces except the interface on which it was received. For example, if a switch in the figure were to receive a broadcast, it would forward it to the other switches and other users connected in the network.

Question 40

What is the problem with large broadcast domain?

Answer 40

The problem with a large broadcast domain is that these hosts can generate excessive broadcasts and negatively affect the network. This results in slow network operations due to the significant amount of traffic it can cause, and slow device operations because a device must accept and process each broadcast packet.

Question 41

What is the solution to the large broadcast domain problem?

Answer 41

The solution is to reduce the size of the network to create smaller broadcast domains in a process called subnetting. These smaller network spaces are called subnets.

Question 42

What are the reasons for using subnetting?

Answer 42

Subnetting reduces overall network traffic and improves network performance. It also enables an administrator to implement security policies such as which subnets are allowed or not allowed to communicate together. Another reason is that it reduces the number of devices affected by abnormal broadcast traffic due to misconfigurations, hardware/software problems, or malicious intent.

Question 43

What are some examples of of how network administrators can group devices and services into subnets?

Answer 43

• Subnetting by Location:
  Per every floor, there is a switch which its in own subnets.
• Subnetting by Group or Function: This is subnetting by department on a company. Like Admin, IT, Sales, HR etc.
• Subnetting by device types: All Hosts, All Printers, All Servers