The Internet Protocol Eliot Grove Danny Friel Stuart Anderson

OSI Model Application Presentation Session Transport Network Data Link Physical

The Network Layer Navigating data Source Destination

Internet Protocol Numbering scheme Largest network of computers American Registry of Internetwork Numbers (ARIN)

What is an IP address A way to identify machines on a network A unique identifier

IP usage Used to connect to another computer Allows transfers of files and e-mail If you want to connect to another computer, transfer files to or from another computer, or send an e-mail message, you first need to know where the other computer is - you need the computer's "address." An IP (Internet Protocol) address is an identifier for a particular machine on a particular network; it is part of a scheme to identify computers on the Internet. IP addresses are also referred to as IP numbers and Internet addresses

IP structure IP addresses consist of four sections Each section is 8 bits long Each section can range from 0 to 255 Written, for example, 128.35.0.72 An IP address consists of four sections separated by dots. Commonly written in decimal Each section contains a number ranging from 0 to 255. Example = 128.35.0.72

IP structure These four sections represent the machine itself and the network it is on The network portion is assigned. The host section is determined by the network administrator These four sections represent both the machine itself, or host, and the network that the host is on. The network portion of the IP address is allocated under authority of the Internet Assigned Numbers Authority (IANA). American Registry of Internetwork Numbers (ARIN) Network administrators then assign the host portion of the IP address to the machines on the networks that they operate

IP structure 5 Classes of IP address A B C D and E Class A reserved for governments Class B reserved for medium companies Class C reserved for small companies Which sections of the IP address represent the network and which sections represent the machine will depend on what "class" of IP address is assigned to a network. There are 5 classes of IP addresses: Class A, Class B, Class C, Class D, and Class E.   Class A - supports 16 million hosts on each of 127 networks Class B - supports 65,000 hosts on each of 16,000 networks Class C - supports 254 hosts on each of 2 million networks

IP structure Class D are reserved for multicasting Class E are reserved for future use

IP structure Class A begins 1 to 126 Class B begins 128 to 191 Class C begins 192 to 223 Classes correspond either to the size of the network (the number of hosts that the network can support) or are reserved for specific purposes, such as multicasting and experimentation. The diagram shows Class A, Class B and Class C IP addresses. The blue numbers represent the network and the red numbers represent hosts on the network. As has been mentioned, a Class A network can support many more hosts than a Class C network. You can determine which class any IP address is in by examining the first 4 bits of the IP address. Class A addresses begin with 0xxx, or 1 to 126 decimal. Class B addresses begin with 10xx, or 128 to 191 decimal. Class C addresses begin with 110x, or 192 to 223 decimal. Class D addresses begin with 1110, or 224 to 239 decimal. Class E addresses begin with 1111, or 240 to 254 decimal. Addresses beginning with 01111111, or 127 decimal, are reserved for loopback and for internal testing on a local machine. [You can test this: you should always be able to ping 127.0.0.1, which points to yourself] Class D addresses are reserved for multicasting. Class E addresses are reserved for future use. They should not be used for host addresses.

Reserved addresses Addresses beginning 127 are reserved for loopback and internal testing xxx.0.0.0 reserved for network address xxx.255.255.255 reserved for broadcast Loopback Routers use the network address in the forwarding of data. Also, Hosts can only communicate directly with devices using the same network address. Broadcast allows a message to be sent to all devices on a network

IP Addresses IP addresses are: Unique Global and Standardised Essential IP addresses are unique. No two machines can have the same IP number. IP addresses are also global and standardized. All machines connected to the Internet agree to use the same scheme for establishing an address.

Subnetting - Why? Division of local networks Greater number of networks Simplifies addressing

Subnetting - How Bits borrowed from host field Network Host Network Subnet/Host

Subnetting -Example 130.5.0.0 - Network address 130.5.2.144 - Host address 255.255.255.0 - Subnet Mask 130.5.2.0 - Subnet

Where do you want to go Tomorrow? Computer controlled dwellings Road and rail systems Criminal tagging

The Internet Protocol Running out!! Upgraded to IPv6

Thank you!

And goodnight!