nation MAC address. The packet is placed on the ethernet network and every machine, actually the ethernet card, on the network looks at the packet. If the card recognises the destination MAC as its own it "grabs" the packet and passes it to the Network access layer. This only works when the machines are on the same physical ethernet network.4.2 INTERNET ADDRESSESA) Internet addressesOne of the responsibilities of the Internet protocol is to define the Internet addressing scheme. TCP/IP networking software and protocols use the IP addressing scheme to route and distribute information.TCP/IP addresses are currently 32 bit numbers that are usually represented by four 8 bit (octets) numbers separated by full stops (called dotted decimal form) e.g. 132.22.42.1. Using 8 bits the maximum range that can be represented is 0-255 (256 numbers). This means that 257.33.33.22 is an invalid address.For example :The IP address 132.22.42.1 is actually stored as a 32 bit binary number. Each of the four decimal numbers above representing one byte of the final binary number132= 1000010022 = 0001011042 = 001010101 = 00000001Final number is ;10000100 00010110 00101010 00000001B)Addresses and InterfacesA common misconception is that an IP address belongs to the machine. For example the machine cq-pan.cqu.edu.au has the IP address 138.77.37.37. This statement is slightly incorrect. In actual fact it is the ethernet card on cq-pan that has the IP address.IP addresses are assigned to network interfaces. A network interface might be an ethernet card, a SLIP connection over a modem, a token ring card or any other form of network connection. It is possible for one machine or device to actually have multiple network interfaces and therefore have multiple IP addresses.= Figure 3 =An ethernet network card4.3 GATEWAYS AND IP ADDRESSESA) Gateways and IP addressesGateways and routers are able to distribute data from one network to another because they are actually ph...
