topic 6A : ipv4 addressing

Question 1

how many bits are in an ipv4 address?

Answer 1

32 bits

Question 2

how many octets are there? and how many bits are there in an octet?

Answer 2

4 octets and 8 bits in each octet

Question 3

what is the decimal range of each octet?

Answer 3

0 to 255

Question 4

ipv4 address structure

Answer 4

[192.168.10] .[1]
network portion / host portion

Question 5

binary number system

Answer 5

only two digits : 0 and 1

Question 6

how to convert a binary address to decimal?

Answer 6

1st decimal : 2^7 = 128
2nd decimal : 2^6 = 64
3rd decimal : 2^5 = 32
4th decimal : 2^4 = 16
5th decimal : 2^3 = 8
6th decimal : 2^2 = 4
7th decimal : 2^1 = 2
8th decimal : 2^0 = 0

Question 7

converting from decimal to binary

Answer 7

a series of steps starting from the leftmost bit of the octet

one eg : converting 168 to binary
168 >= 128 so 168-128=40
but if the number is not >= the octet bit value then move on to the next value.

Question 8

ipv4 address and subnet mask

Answer 8

(EXAMPLE) when subnet mask is /16, the network portion of the ipv4 address is the first 16 digits of the binary form of the ipv4 address, and the rest of it is the host portion

Question 9

IPv4 network, host and broadcast address

Answer 9

when the host portion is :
all 0s -> network address
0’s and 1’s -> host address
all 1s -> broadcast address
00000001 -> 1st host address
11111110 -> last host address

Question 10

what is DHCP?

Answer 10

• the preferred method of assigning ipv4 addresses to hosts on large networks because it reduces the burden on network support staff and virtually eliminates entry errors
• enables the automatic assignment of addressing information such as IP address, subnet mask, default gateway and other configuration information