1. IP Addressing Terminology
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2. Binary And Decimal Numbers
Where do our numbers come from?
Where do binary Numbers come from?
Our numbers are Base ten-ten fingers and ten toes
Binary originated with Leibniz (also calculus-developed for logic) Boole-but then found use in computers and electronics

3. Binary vs. Decimal Binary Number 1000 Decimal Number 1000
What is the difference? Write up numbers-1, 2, 4, 8 for Binary-1000 is eight!
Switch to white board and do some examples!
When Converting to Binary-Remember the 8 bit sequence

4. Convert Decimal to Binary
Convert 105
0 ? ? ? ? ? ? ?
0 1 ? ? ? ? ? ?
0 1 1 ? ? ? ? ?
? ? ? ?
? ? ?
= 105
Can I subtract 128? No
Can I subtract 64?
Yes- with 41 left
Can I subtract 32?
Yes-with 9 left
Can I subtract 16?
Can I subtract 8?
Yes-1 left
Can I subtract 4? 2? 1?

5. Convert Binary to Decimal
Convert
Add the decimal number when the bit is a 1
128 32 16 2
__1_
179

6. IP addressing Scheme Dotted-decimal, as in 172.163.30.56
Binary, as in
Hexadecimal, as in AC.10.1E.38 (least likely)

7. IP Address Essential For each class you MUST know
Address Class Range
Reserved Addresses
Default Subnet Mask
Understand Network and Broadcast Address

8. Internet Address Classes
Class A – Range to
Class B – Range to
Class C – Range to
Class D – Range 224 to 239 (network address only)
Class E – Range 240 to 247 (reserved for future use)

9. IP Addressing Rules Loopback address Broadcast address Network address
Special-case source address
Reserved IP addressing

10. Reserved Addresses

11. Class A Structure Range Default Subnet Mask Class A Addresses
Network.node.node.node
Range
through
Default Subnet Mask
Class A Addresses
Valid hosts =
0’s & 255s are valid hosts but hosts bits cannot all be off or on at the same time!
224-2 = 22
Reserved Addresses:
through

12. Class B Structure Range Default Subnet Mask Class B Valid Host IDs
Network.Network.node.node
Range
through
Default Subnet Mask
Class B Valid Host IDs
Valid hosts =
0’s & 255s are valid hosts but hosts bits cannot all be off or on at the same time!
216-2 = 214
Reserved Addresses:
through

13. Class C Structure Network.Network.Network.node Range
through
Default Subnet Mask
Class C Valid Host IDs
Valid hosts =
28-2 = 26
Reserved Addresses:
through

14. IP Addressing Rules Loopback address Anything that starts with 127
Broadcast addresses
Host portion is all 1
Network and special-case source addresses
Host portion is all 0
Reserved IP addressing
As seen on previous slides

15. Subnetworks Subnet masks ANDing
Distinguish the network and host portions of an IP address
Specify whether a destination address is local or remote
ANDing

16. Key Subnetting Ideas If you know the subnet mask, figure out ranges
Subtract Subnet mask from 256
Result is starting network address and block size
Figure out network addresses
Add block size to self up to subnet mask
Figure out Broadcast addresses
One less than next network address
Figure out available addresses
Between Network and Broadcast

17. Figuring Out subnets Figure out how many bits you have to play with
You can steal from the host portion.
How many subnets or hosts are needed?
Use the 2n-2>= what you need formula
Determine the subnet mask
Make the bits you steal into 1’s and the rest into 0’s

18. Key Subnetting Ideas If you know the subnet mask, figure out ranges
Subtract Subnet mask from 256
Result is starting network address and block size
Figure out network addresses
Add block size to self up to subnet mask
Figure out Broadcast addresses
One less than next network address
Figure out available addresses
Between Network and Broadcast

19. Basic Subnetting Example
What is the network address for the following IP address, subnet mask combination:
IP Address
Subnet Mask

20. Basic Subnetting Example
IP Address
Subnet Mask
Step =16
Step 2. 16, 32, 48, 64, 80, 96 (stop when you are past the number in question
Step 3. 31, 47, 63, 79, 95, 111
Step 4. Answer-C

21. Basic Subnetting Example
Which of the following are valid addresses for the following network (Choose 2)
IP Address
Subnet Mask

22. Basic Subnetting Example
IP Address
Subnet Mask
Step =32
Step 2. 32, 64, 96, 128 (only need to go as far as question)
Step 3. 63, 95, 127, 159
Step 4. Network 96 Range
through

23. CIDR Notation and subnet Masks
/ notation shows how many bits are 1 in subnet mask.
For example:
/8 = =
/12= =
/16= =

24. CIDR Notation and subnet Masks
To figure subnet mask from / notation
Step 1. Draw out bits, figure out how many bits are used in subnetted octet
Step 2. For subnetted octect, write out 8 bit number with powers of 2
Step 3. Convert from Binary to Decimal
Step 4. Write our subnet mask
Step 5. Use number to figure Networks, Broadcasts and Ranges.

25. CIDR Example What is the subnet mask for the following address
IP Address: /20

26. CIDR Example IP Address: 140.34.16.240 /20
Step
Step
Step =240
Step
Step 5. Network
Broadcast
Range through

27. Custom Subnet Masks Step 1: Determine the number of subnets needed
Step 2: Determine the number of bits to borrow from the host portion
Step 3: Determine the subnet mask
Step 4: Determine the maximum number of hosts per subnetwork
Step 5: Determine the subnetwork addresses for each subnet
Step 6: Determine the address ranges for each subnetwork

28. Basic Subnetting Example
What is the network address for the following IP address, subnet mask combination:
IP Address
Subnet Mask

29. Basic Subnetting Example
IP Address
Subnet Mask
Step =16
Step 2. 16, 32, 48, 64, 80, 96 (stop when you are past the number in question
Step 3. 31, 47, 63, 79, 95, 111
Step 4. Answer-C

30. Basic Subnetting Example
What is the network address for the following IP address, subnet mask combination:
IP Address
Subnet Mask

31. Basic Subnetting Example
Which of the following are valid addresses for the following network (Choose 2)
IP Address
Subnet Mask

32. Basic Subnetting Example
IP Address
Subnet Mask
Step =32
Step 2. 32, 64, 96, 128 (only need to go as far as question)
Step 3. 63, 95, 127, 159
Step 4. Network 96 Range
through

33. Basic Subnetting Example
Which of the following are valid addresses for the following network (Choose 2)
IP Address
Subnet Mask

34. CIDR Notation and subnet Masks
/ notation shows how many bits are 1 in subnet mask.
For example:
/8 = =
/12= =
/16= =

35. CIDR Notation and subnet Masks
To figure subnet mask from / notation
Step 1. Draw out bits, figure out how many bits are used in subnetted octet
Step 2. For subnetted octect, write out 8 bit number with powers of 2
Step 3. Convert from Binary to Decimal
Step 4. Write our subnet mask
Step 5. Use number to figure Networks, Broadcasts and Ranges.

36. CIDR Example What is the subnet mask for the following address
IP Address: /20

37. CIDR Example IP Address: 140.34.16.240 /20
Step
Step
Step =240
Step
Step 5. Network
Broadcast
Range through

38. CIDR Example What is the subnet mask for the following address
IP Address: /20

39. Custom Subnet Masks Step 1: Determine the number of subnets needed
Step 2: Determine the number of bits to borrow from the host portion
Step 3: Determine the subnet mask
Step 4: Determine the maximum number of hosts per subnetwork
Step 5: Determine the subnetwork addresses for each subnet
Step 6: Determine the address ranges for each subnetwork