Subnet revision

1
Subnet revision
SMlink
Mansfield LAN
Skegby LAN
DMlink
NMlink
Nottingham LAN
Derby LAN
DNlink

• Use network 192.168.1.0/24 No VLSM
• Subnet zero and last subnet can be used

2
Subnet revision 192.168.1.0/24
SMlink
Mansfield LAN
Skegby LAN
DMlink
NMlink
Nottingham LAN
Derby LAN
DNlink

• How many subnets do you need?
• 8

3
Subnet revision 192.168.1.0/24
SMlink
Mansfield LAN
Skegby LAN
DMlink
NMlink
Nottingham LAN
Derby LAN
DNlink

• How many bits must you borrow for 8 subnets?
• 3

4
Subnet revision 192.168.1.0/24
SMlink
Mansfield LAN
Skegby LAN
DMlink
NMlink
Nottingham LAN
Derby LAN
DNlink

• What is the subnet mask if 3 bits borrowed?
• 255.255.255.224

5
Subnet revision 192.168.1.0/24
SMlink
Mansfield LAN
Skegby LAN
DMlink
NMlink
Nottingham LAN
Derby LAN
DNlink

• How many bits remain for host addressing?
• 5

6
Subnet revision 192.168.1.0/24
SMlink
Mansfield LAN
Skegby LAN
DMlink
NMlink
Nottingham LAN
Derby LAN
DNlink

• How many addresses on each subnet and how many
  can be used for hosts?
• 32 total, 30 can be used.

7
Fill in the table
8
Completed table
9
Subnet revision 192.168.1.0/24

• What is the largest number of hosts you can have
  on any subnet?
• 30
• How many addresses are wasted on one serial link?
• 28
• How many addresses are wasted on all 4 serial
  links?
• 112

10
Subnet with VLSM 192.168.1.0/24
Mansfield LAN25 hosts
Skegby LAN10 hosts
SMlink
Nottingham LAN50 hosts
SDlink
MNlink
Derby LAN100 hosts
DNlink

• Can you subnet without VLSM and have enough hosts
  on each subnet?
• No

11
Subnet with VLSM 192.168.1.0/24
Mansfield LAN25 hosts
Skegby LAN10 hosts
SMlink
Nottingham LAN50 hosts
SDlink
MNlink
Derby LAN100 hosts
DNlink

• What is the largest subnet and how many hosts?
• Derby, 100 hosts

12
Subnet with VLSM 192.168.1.0/24
Mansfield LAN25 hosts
Skegby LAN10 hosts
SMlink
Nottingham LAN50 hosts
SDlink
MNlink
Derby LAN100 hosts
DNlink

• How many host bits do you need for 100 hosts?
• 7 bits, gives 126 hosts

13
Subnet with VLSM 192.168.1.0/24
Mansfield LAN25 hosts
Skegby LAN10 hosts
SMlink
Nottingham LAN50 hosts
SDlink
MNlink
Derby LAN100 hosts
DNlink

• How many bits borrowed? Subnet mask?
• 1 bit. 255.255.255.128, /25

14
Fill in first row of table

• 1 bit borrowed. 255.255.255.128, /25
• Using 192.168.1.0/24

15
First row of table

• What is the next subnet address?
• 192.168.1.128

16
Subnet with VLSM 192.168.1.0/24
Mansfield LAN25 hosts
Skegby LAN10 hosts
SMlink
Nottingham LAN50 hosts
SDlink
MNlink
Derby LAN100 hosts
DNlink

• What is the next largest subnet and how many
  hosts?
• Nottingham, 50 hosts

17
Subnet with VLSM 192.168.1.0/24
Mansfield LAN25 hosts
Skegby LAN10 hosts
SMlink
Nottingham LAN50 hosts
SDlink
MNlink
Derby LAN100 hosts
DNlink

• How many host bits do you need for 50 hosts?
• 6 bits, gives 62 hosts

18
Subnet with VLSM 192.168.1.0/24
Mansfield LAN25 hosts
Skegby LAN10 hosts
SMlink
Nottingham LAN50 hosts
SDlink
MNlink
Derby LAN100 hosts
DNlink

• How many bits borrowed? Subnet mask?
• 2 bits. 255.255.255.192, /26

19
Fill in next row of table

• 2 bits borrowed. 255.255.255.192, /26
• Using 192.168.1.0/24

20
Second row of table

• What is the next subnet address?
• 192.168.1.192

21
Subnet with VLSM 192.168.1.0/24
Mansfield LAN25 hosts
Skegby LAN10 hosts
SMlink
Nottingham LAN50 hosts
SDlink
MNlink
Derby LAN100 hosts
DNlink

• What is the next largest subnet and how many
  hosts?
• Mansfield, 25 hosts

22
Subnet with VLSM 192.168.1.0/24
Mansfield LAN25 hosts
Skegby LAN10 hosts
SMlink
Nottingham LAN50 hosts
SDlink
MNlink
Derby LAN100 hosts
DNlink

• How many host bits do you need for 25 hosts?
• 5 bits, gives 30 hosts

23
Subnet with VLSM 192.168.1.0/24
Mansfield LAN25 hosts
Skegby LAN10 hosts
SMlink
Nottingham LAN50 hosts
SDlink
MNlink
Derby LAN100 hosts
DNlink

• How many bits borrowed? Subnet mask?
• 3 bits. 255.255.255.224, /27

24
Fill in next row of table

• 3 bits borrowed. 255.255.255.224, /27
• Using 192.168.1.0/24

25
Third row of table

• What is the next subnet address?
• 192.168.1.224

26
Subnet with VLSM 192.168.1.0/24
Mansfield LAN25 hosts
Skegby LAN10 hosts
SMlink
Nottingham LAN50 hosts
SDlink
MNlink
Derby LAN100 hosts
DNlink

• What is the next largest subnet and how many
  hosts?
• Skegby, 10 hosts

27
Subnet with VLSM 192.168.1.0/24
Mansfield LAN25 hosts
Skegby LAN10 hosts
SMlink
Nottingham LAN50 hosts
SDlink
MNlink
Derby LAN100 hosts
DNlink

• How many host bits do you need for 10 hosts?
• 4 bits, gives 14 hosts

28
Subnet with VLSM 192.168.1.0/24
Mansfield LAN25 hosts
Skegby LAN10 hosts
SMlink
Nottingham LAN50 hosts
SDlink
MNlink
Derby LAN100 hosts
DNlink

• How many bits borrowed? Subnet mask?
• 4 bits. 255.255.255.240, /28

29
Fill in next row of table
30
Fourth row of table
31
Subnet with VLSM 192.168.1.0/24
Mansfield LAN25 hosts
Skegby LAN10 hosts
SMlink
Nottingham LAN50 hosts
SDlink
MNlink
Derby LAN100 hosts
DNlink

• How many hosts on a point to point link?
• 2

32
Subnet with VLSM 192.168.1.0/24
Mansfield LAN25 hosts
Skegby LAN10 hosts
SMlink
Nottingham LAN50 hosts
SDlink
MNlink
Derby LAN100 hosts
DNlink

• How many host bits needed for 2 hosts?
• 2

33
Subnet with VLSM 192.168.1.0/24
Mansfield LAN25 hosts
Skegby LAN10 hosts
SMlink
Nottingham LAN50 hosts
SDlink
MNlink
Derby LAN100 hosts
DNlink

• How many bits borrowed? Subnet mask?
• 6 bits. 255.255.255.252, /30

34
Complete last 4 rows of table
35
Last 4 rows of table
36
Subnet with VLSM 192.168.1.0/24
Mansfield LAN25 hosts
Skegby LAN10 hosts
SMlink
Nottingham LAN50 hosts
SDlink
MNlink
Derby LAN100 hosts
DNlink

• You can just about address these networks using
  192.168.1.0/24 with VLSM.
• Its very tight, hardly any room for expansion.