1. Networking The TCP-IP Protocol Suite (Part 2) Carl Smith National Certificate Parts adapted from HNC lectures by Steve Leggett – 2002/03

2.  Developed by the American Defence Department.  Internet Protocol (IP).  Addresses both LAN's and WAN's.  IP information is sent in the form of packets. What is IP?

3. IP Packet Source Address Destination Address Data Checksum CRC

4. IP addresses fall into 3 main categories: Class A, Class B and Class C IP addresses consist of 4 bytes (32 bits) in the form AAA.BBB.CCC.DDD Every interface should have an IP address. IP Addressing

5. IP Addressing... s1 s0 e0 t0 144.98.100.1 144.98.200.1 144.98.30.1 144.98.40.1

6. Class A network - NETWORK.HOST.HOST.HOST 1.0.0.0 through to 126.0.0.0 (16.7 million possible hosts) Class B network - NETWORK.NETWORK.HOST.HOST 128.0.0.0 through to 191.255.0.0 (65,536 possible hosts) Class C network - NETWORK.NETWORK.NETWORK.HOST 192.0.0.0 through to 223.255.255.0 (256 possible hosts) Class D – start at 224.0.0.0 are used for multicasting purposes Class E – start at 240.0.0.0 are used for research purposes IP Addressing…

7. Class A address: 10.xxx.xxx.xxx Class B addresses: 147.119.xxx.xxx, 144.98.xxx.xxx Class C addresses: 192.2.101.xxx, 221.190.45.xxx NB – The number of usable hosts is two less than the total number possible because all zeros or all ones cannot be used. IP Address examples

8. An address using all zero bits is used to specify the actual network, whilst an address of all ones is a broadcast address destined for every user on the network. Defined by RFC 1918 – networks and addresses 10.0.0.0 through to 10.255.255.255, 172.16.0.0 through to 172.31.255.255 and 192.168.0.0 through to 192.168.255.255 These are reserved to be used only as internally private addresses – not to connect to the Internet. IP Addressing

9. Segments the network into smaller sub-networks of the whole network. Manipulates the HOST portion of the address: 144.98.xxx.xxx In IP router networks each router interface must have a separate subnet address. Sub-netting

10. IP Addressing and Sub-netting 144.98.1.1 144.98.1.2 144.98.10.1 144.98.20.1 144.98.30.1 144.98.2.1 144.98.2.2 144.98.20.2 144.98.30.2 144.98.10.2 144.98.30.3 144.98.20.3 144.98.10.2

11. IP Subnets are defined by using a subnet mask. The mask denotes how many bits of the host portion of the address describe the subnet 144.98.subnet.host This mask is a 32 bit Internet address with all ones in the network and subnet portion of the address. Subnet Masks

12. Subnet Masks… 128 64 32 16 8 4 2 1 NETWORK SUBNETHOST 144 98 542 Class 'B' Address 8 bits 128 64 32 16 8 4 2 1 0 1 1 0 0 0 1 01 0 1 0 0 0 0 0 0 0 1 1 0 1 1 0 0 0 0 0 0 0 1 1 128 64 32 16 8 4 2 1 1 1 1 1 1 1 1 11 1 1 1 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 255 0

13. 255.255.255.0 8 bits used for the subnet address and 8 bits for the host address. This means that the 8 bits in the host portion allows 254 hosts and the 8 bits in the subnet portion allows 254 subnets. 255.255.255.192 we have taken two bits of the host portion of the address and used it for the subnet portion. Subnet Masks…

14. 0 1 1 0 0 0 1 01 0 1 0 0 0 0 0 0 0 1 1 0 1 1 0 0 0 0 0 0 0 1 1 128 64 32 16 8 4 2 1 NETWORK SUBNETHOST 144 98 542 Class 'B' Address 8 bits 128 64 32 16 8 4 2 1 8 9 10 11

15. Summary