subnetting

Question 1

what is subnetting

Answer 1

• allocating 1 IP address range to several networks.
• partition adress space into multiple smaller networks (subnets)
• all hosts in same subnet have the same subnet number (network address)

Question 2

why do we need subnetting

Answer 2

• IP exhaustion
• efficient address spacing
• security
• efficient broadcast domain

Question 3

class A

Answer 3

first bits = 0
7 bit network
24 bit host

Question 4

class B

Answer 4

first bits = 10
14 bit network
16 bit host

Question 5

class C

Answer 5

first bits = 110
21 bit network
8 bit host

Question 6

how to find out how many possible hosts in a network?

Answer 6

let n = # of host bits
ex: class A: n = 24

hosts = 2^24 - 2
minus 2 since the first address is the net ID and the last address is the broadcast address

Question 7

what is the subnet mask

Answer 7

shows 1’s for all bits that are apart of the network address

Question 8

determine the subnet number from the subnet mask and ip address

Answer 8

in binary write the ip address under the subnet mask and all the bits of ip aligning with 1’s from mask are apart of the subnet number.

Question 9

broadcast address

Answer 9

the last available address of a network

Question 10

network address

Answer 10

the first availible address of a network

Question 11

DHCP

Answer 11

• a way to automate host configuration
• a new host on a network sends a request to the DHCP server who responds with assignment and info
• each admin domain has at least 1 DHCP server