week 8

Question 1

what is the formula to calculate no of host s

Answer 1

2^host bits - 2

Question 2

what does subnet mask/prefix determine

Answer 2

size of the subnet

Question 3

how many ways can a host communicate in ipv4 network

Answer 3

3 ways

unicast
multicast
broadcast

Question 4

what is unicast

Answer 4

it is the process of sending packets from 1 host to an individual host

Question 5

what is broadcast

Answer 5

it is the process of sending a packet from 1 host to all hosts in the network

Question 6

routers do not forward a __________-

Answer 6

limited broadcast

Question 7

what is multicast

Answer 7

the process of sending a packet from one host to a group of hosts in the network which subscribes to a special range of addresses known as multicast address

Question 8

what are private ip address blocks

Answer 8

hosts that do not require direct access to the internet can use private addresses

Question 9

examples of private ip

Answer 9

• 10.0.0.0 to 10.255.255.255 (10.0.0.0/8)
• 172.16.0.0 to 172.31.255.255 (172.16.0.0/12)
• 192.168.0.0 to 192.168.255.255 (192.168.0.0/16)

Question 10

what are public ip blocks

Answer 10

most of the addresses which are publicly accessible from the internet

some addresses are set aside for special purposes

Question 11

what are the different types of special IPv4 addresses

Answer 11

network and broadcast address - first and last addresses within a network

loopback address - 127.0.0.1 is a special address that hosts use to direct traffic to themselves (addresses 127.0.0.1 and 127.255.255.255)

link local address - 169.254.0.0 to 169.254.255.255 are automatically assigned to local host

TEST-net address - 192.0.2.0 to 192.0.2.255 are set aside for teaching and learning purposes, used in documentation and network examples

Experimental addresses - 240.0.0.0 to 255.255.255.254 are listed as reserved

Question 12

what is class A address

Answer 12

• -> uses a prefix of /8
• -> most significant bit of a higher order octet is a 0 ([0]0000000 - [0]1111111)
• -> this means that there are only 128 possible class A networks

Question 13

what is a class B address

Answer 13

• -> uses a fixed /16 prefix
• -> the most significant bits of the higher order octet is 10 ([10]000000 - [10]111111)
• -> The address block for class B is 128.0.0.0/16 to 192.255.0.0/16

Question 14

What is a class C address

Answer 14

• -> uses a /24 prefix
• -> it uses only the last octet as host addresses with the three high order octets used for the network address
• ->The most significant 3 bits of the higher order octet is 110 ([110]00000 - [110]111111)
• -> The address block is 192.0.0.0/24 to 223.255.255.0/24

Question 15

what are the problems with legacy classful addressing

Answer 15

• -> there are not more than 128 class A blocks, 16384 class B blocks and 2,097,150 Class C blocks
• -> Insufficient for the modern world
• -> A company that needs 260 addresses will be assigned class B block which will lead to wastage of many addresses

Question 16

what is classless addressing also called

Answer 16

classless interdomain routing (CIDR)

Question 17

what is the purpose of CIDR

Answer 17

created a new set of standards that allowed service providers to allocate IPv4 addresses on any address bit boundary instead of class A,B or C addres

Question 18

what determines the network and host portion

Answer 18

subnet mask

Question 19

__________ does not matter in CIDR

Answer 19

value of the first octet

Question 20

where is CIDR used

Answer 20

used within the internet and in most internal networks