1. IP Address 32 bits in length Contains two parts –Network number –Host number Binary in nature Expressed in a format that can be read by the human eye

2. IP Address Sections Broken into 4 sections of 8 bits called octets Each octet is converted to decimal format and is separated by dots 255.255.255.255 11111111|11111111|11111111|11111111 172.16.122.204 10101100|00010000|01111010|11001100

3. Octets Minimum octet value is 0 – all zeros Maximum octet value is 255 – all ones

4. Address Allocation Addresses are allocated by a central authority, the American Registry of Internetwork Numbers (ARIN) See www.arin.net for more informationwww.arin.net

5. Early IP Addresses Early IP addresses did not use classes because there weren’t very many networks Now a class system is necessary to increase the number of available IP addresses

6. IP Address Classes 8 Bits Class ANetworkHost Class BNetwork Host Class CNetwork Host Class DMulticast Class EResearch

7. Analysis of Class System Class A networks have only 8 network bits and 24 host field bits Therefore, there are few Class A networks There are more Class B networks and even more yet Class C networks each with fewer hosts Class system allows addresses to be assigned based on the size of the network There are many more small networks than there are large networks

8. Address Classification Bits:1 89 1617 2425 32 Class A:0NNNNNNNHost Range(1–126) Bits:1 89 1617 2425 32 Class B:10NNNNNNNetworkHost Range(128–191) Bits:19 1617 2425 32 Class C110NNNNNNetwork Host Range(192–223)

9. Class Ranges Class AClass BClass C Starts with:010110 Range:1.0.0.0 to 126.0.0.0 128.0.0.0 to 191.255.0.0 192.0.0.0 to 223.255.255.0 Networks:127 (1-126) 127 is reserved 16,3842,097,152 Hosts:16,777,216 – 265,536 – 2256 – 2

10. Class D – Multicast Addresses Bits:1 89 1617 2425 32 Class D:1110MMMMMulticast Grp Range(224–239) Includes the following range of network numbers: 224.0.0.0 to 239.255.255.255

11. Class E – Research Addresses Bits:1 89 1617 2425 32 Class E:11110RRRResearch Grp Range(240–247) Includes the following range of network numbers: 240.0.0.0 to 247.255.255.255

12. Reserved Addresses RFC 1918 defines the following as reserved addresses: 10.0.0.0 through 10.255.255.255 172.16.0.0 through 172.31.255.255 192.168.0.0 through 192.168.255.255

13. Host Addresses 10.250.8.11 Router 10.6.24.2 E1 10.180.30.118 172.16.2.100 E0 172.16.2.1 172.16.12.12 172.16.3.10 10.1.1.1 RoutingTable NetworkInterface 172.16.0.0E0 10.0.0.0E1

14. Host Address Conventions Host address of 0 means this network or wire address, i.e., 172.16.0.0 Router uses network address to identify subnet Routing table contains entries for each network All 1s is a broadcast address. Number of addresses in network is 2 N – 2

15. Default Subnet Masks ClassFormatDefault Subnet Mask Anetwork.node.node.node255.0.0.0 Bnetwork.network.node.node255.255.0.0 Cnetwork.network.network.node255.255.255.0

16. Subnet Example 172.16.3.100 Router 172.16.3.1 E1 172.16.3.150 172.16.2.200 E0 172.16.2.1 172.16.2.160 172.16.2.2 172.16.3.5 RoutingTable NetworkInterface 172.16.2.0E0 172.16.3.0E1

17. Subnet Mask Example network host IP Address1721600 network host Default Mask 255 00 written as:/16 network subnethost Subnet Mask 255 0 written as:/24

18. Subnet Mask Numbering 1 for network bits 1 for subnet bits 0 for host bits

19. Methods of Representation Dotted Decimal – 172.16.0.0 255.255.0.0 Bit Count – 172.16.0.0/16 Hexadecimal – 172.16.0.0xFFFF0000

20. Possible Subnet Mask Values 10000000=128 11000000=192 11100000=224 11110000=240 11111000=248 11111100=252 11111110=254 11111111=255

21. Calculating Network Number – No Subnet Bits /16 network host 172.16.2.16010101100000100000000001010100000 255.255.0.011111111 00000000 101011000001000000000000 Network Number1721600

22. Calculating Subnet Number – 8 Subnet Bits /24 network host 172.16.2.16010101100000100000000001010100000 255.255.0.011111111 00000000 10101100000100000000001000000000 Subnet Number1721620

23. Calculating Subnet Number – 10 Subnet Bits /26 network subnethost 172.16.2.160101011000001000000000010 10100000 255.255.0.011111111 11111111 11000000 101011000001000000000010 10000000 Subnet Number17216 2128

24. Class B Broadcasts From 172.16.1.12 Local to Subnet 1 – 255.255.255.255 Specific to Subnet 3 – 172.16.3.255 To All Subnets – 172.16.255.255

25. Defining Class B Subnet – /26 172.16.2.160101011000001000000000010 10100000host 255.255.255.19211111111 11111111 11000000mask 172.16.2.128101011000001000000000010 10000000subnet 172.16.2.191101011000001000000000010 10111111broadcast 171.16.2.129101011000001000000000010 10000001first 171.16.2.190101011000001000000000010 10111110last

26. Defining Class B Subnet – /24 172.16.2.12110101100000100000000001010100000host 255.255.255.011111111 00000000mask 172.16.2.010101100000100000000001000000000subnet 172.16.2.25510101100000100000000001011111111broadcast 171.16.2.110101100000100000000001000000001first 171.16.2.25410101100000100000000001011111110last

27. Possible Class B Combinations bitssubnet masksubnetshosts 2255.255.192.0216382 3255.255.224.068190 4255.255.240.0144094 5255.255.248.0302046 6255.255.252.0621022 7255.255.254.0126510 8255.255.255.0254 9255.255.255.128510126 10255.255.255.192102262 11255.255.255.224204630 12255.255.255.240409414 13255.255.255.24881906 14255.255.255.252163822

28. Network Design Class C Network with address 172.16.2.121 Supports at least 20 subnets – 5 bits Each Subnet has at least 5 hosts – 3 bits

29. Class C Network Specifications – /29 network subnethost 192.168.5.12111000000101010000000010101111001host 255.255.255.24811111111 11111000mask 192.168.5.12011000000101010000000010101111000subnet 192.168.5.12711000000101010000000010101111111broadcast 192.168.5.12111000000101010000000010101111001first 192.168.5.12611000000101010000000010101111110last

30. Possible Class C Combinations bitssubnet masksubnetshosts 2255.255.255.192262 3255.255.255.224630 4255.255.255.24014 5255.255.255.248306 6255.255.255.252622