Chapter 6 - TCP/IP Basics

Question 1

How many bits does an IPV4 address consists of?

Answer 1

32 bits (8 octets).

Question 2

Identify the network ID section of the following IP address and subnet mask : 10.14.12.43-255.255.255.0

Answer 2

Network ID : 10.14.12.x
Host ID : x.x.x.43

Question 3

What does ARP stands for?

Answer 3

Address Resolution Protocol.

Question 4

Identify the class of the following IP address : 146.203.143.101

Answer 4

Class B.

Question 5

What is the maximum number of hosts in a /19 subnet?

Answer 5

8190, the all zero and all one hosts are reserved.

Question 6

What is the number 138 in binary?

Answer 6

128+8+2 = 10001010

Question 7

When a DHCP discover fails, what process will the client use to generate an address for itself?

Answer 7

APIPA (Automatic Private IP Addressing) will start with 169.

Question 8

At which layers of the IP model does the TCP/IP suites sits?

Answer 8

Application, Transport and Internet. TCP/IP applications do not include the link layer.

Question 9

Name 3 mains internet layer TCP/IP protocols.

Answer 9

IPv4, IPv6, ICMP (Internet Control Message Protocol).

Question 10

Name 2 transport layver TCP/IP protocols.

Answer 10

TCP and UDP.

Question 11

What’s the range of a Class A address?

Answer 11

1.0.0.0 - 126.255.255.255

Question 12

What’s the range of a Class B address?

Answer 12

128.0.0.0 - 191.255.255.255

Question 13

What’s the range of Class C address?

Answer 13

192.0.0.0 - 223.255.255.255

Question 14

What’s the range of Class D address?

Answer 14

224.0.0.0 - 239.255.255.255

Question 15

What’s the range of Class E address?

Answer 15

240.0.0.0 - 254.255.255.255

Question 16

What’s the difference between subnetting and CIDR?

Answer 16

Subnetting and CIDR (Classless Inter-Domain Routing) are both techniques used in IP addressing and routing, but they differ in their approaches.

Subnetting:
Subnetting is a method of dividing a larger network into smaller, more manageable sub-networks or subnets. It involves borrowing bits from the host portion of an IP address to create distinct sub-networks. Subnetting is typically associated with classful addressing (Class A, B, or C) and uses fixed subnet masks.

CIDR:
CIDR, on the other hand, is a more flexible addressing scheme that allows for variable-length subnetting. It eliminates the rigid class boundaries and uses a prefix notation to represent IP address blocks. In CIDR, a prefix length is specified in the form of “/X,” where X indicates the number of bits in the network portion of the address.

In summary, subnetting is a method of dividing a network into fixed-size subnets within the traditional classful addressing, while CIDR is a more modern approach that provides flexibility in defining variable-sized subnets using a prefix notation.

Question 17

What protocol would you use for dynamic IP addressing?

Answer 17

DHCP (Dynamic Host Configuration Protocol).

Question 18

What’s the 4 way handshake of DHCP?

Answer 18

DORA, Discover, Offer, Request Ack.

Question 19

What’s the 3 way handshake of TCP?

Answer 19

Syn, Syn Ack, Ack.

Question 20

What is a DHCP relay used for?

Answer 20

A DHCP relay is used to facilitate the dynamic assignment of IP addresses in networks where the DHCP (Dynamic Host Configuration Protocol) server is located on a different subnet than the requesting client devices. DHCP operates at the application layer to automatically assign IP addresses and other network configuration information to devices on a network.

The DHCP relay agent helps relay DHCP messages between DHCP clients and servers across different subnets. When a DHCP client sends a DHCP request to obtain an IP address, the relay agent intercepts the request and forwards it to the DHCP server. The DHCP server, which may be on a different subnet, processes the request and sends the DHCP response back to the relay agent. The relay agent then forwards the DHCP response to the client, allowing it to obtain the assigned IP address and other configuration details.

In essence, a DHCP relay enables the centralized management of IP address allocation in a network with multiple subnets by forwarding DHCP messages between clients and servers across different network segments.

Question 21

What are the 2 ways to introduce redundancy in your DHCP servers?

Answer 21

You can have a failover (secondary DHCP that remains dormant until the main fails, it has the same scope as the primary), or you can split your scope between multiple DHCP.

Question 21

What are the 2 way to reserve address in a DHCP server?

Answer 21

DHCP reservation (block address from the DHCP scope) and MAC reservation (the same MAC address always get the same IP address).