Subnetting

1. Subnetting

2. Subnetting • Binary to Decimal Conversion • Decimal to Binary Conversion • Classes of IP Addresses • Subnet Masks • 7 step method to practical subnetting • Class C • Class B

3. Binary to Decimal Conversion

4. Binary to Decimal Conversion • Place Card Method

5. Binary to Decimal Conversion Place Card Method for 1100 0000 192 = 128 + 64 + 0 + 0 + 0 + 0 + 0 + 0

6. Binary to Decimal Conversion Place Card Method for 1111 0000 240 = 128 + 64 + 32 + 16 + 0 + 0 + 0 + 0

7. Decimal to Binary Conversion Place Card Method for 129 129 = 128 + 0 + 0 + 0 + 0 + 0 + 0 + 1

8. Decimal to Binary Conversion Place Card Method for 129 129 = 128 + 0 + 0 + 0 + 0 + 0 + 0 + 1

9. Decimal to Binary Conversion Place Card Method for 255 129 = 128 + 64 + 32 +16 + 8 + 4 + 2 + 1

10. IP Address • Example of an IP address is 148.8.20.10 (4 octets) • Each octet is an 8 bit binary number • Therefore, an IP address is 32 bits.

11. IP Address • Each IP address is broken up into a Network Address and a Host address

12. IP Address Classes

13. IP Address Classes A . B . C . D

14. Subnet Masks • Tells the device which bits are host address and network address.

15. Subnetting • What is subnetting • Process of subdividing a single class of network into multiple subnetworks. • A subnetted network address contains a network address, subnet address and host address.

16. Subnetting

17. Subnetting • Why subnet • Reduce Collision Domain • Makes it easier to manage your network (lower TCO) • Makes you network more secure

18. Class C Subnet Example – Assigned 200.10.20.0

19. 1.) Determine # of subnets

20. 2.) Determine # of bits you can borrow For a class C address we have 8 host address bits to work with. You need to borrow at least 2 bits for the subnet address and you must leave at least 2 host bits for the host address. Therefore, we can borrow 2 to 6 bits on a class C address.

21. 3.) Determine # of bits you need to borrow • 2^n -2 = number of useable subnets

22. 4.) High Order Bits • Set the high order bits (determined above) to 1.

23. 5.) Subnet Mask • Combine the Default Subnet Mask with value determined in step #4.

24. 6.) Determine the IP range of each subnet. 5 host address bits or 2^5 hosts per subnet

25. 7.) Determine Range of IP Addresses in each subnet • We’ve determined that there are 32 hosts per subnet.

26. 7.) Determine Range of IP Addresses in each subnet • We’ve determined that there are 32 hosts per subnet.

27. Useable IP addresses • We discard the 1st and last subnet • Discard the 1st and last IP address in each subnet. • Our 1st useable IP address in the first useable subnet that can be assigned to a node on our network would be: • 200.10.20.33