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Addressing. Objectives. Addressing in the LAN IP address es MAC address es. Addressing. Mailbag: MAC addresses on it. Envelope: IP addresses on it. Letter. Data. Packet. Frame. Data = payload = what we pay for. Addressing. MAC Dest: 00:00:00:00:03:01, MAC Src: 00:00:00:00:03:02.
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Objectives • Addressing in the LAN • IP addresses • MAC addresses
Addressing Mailbag: MAC addresses on it Envelope: IP addresses on it Letter Data Packet Frame Data = payload = what we pay for
Addressing MAC Dest: 00:00:00:00:03:01, MAC Src: 00:00:00:00:03:02 IP Dest: 192.168.1.2, IP Src: 192.168.3.2 Letter Data Packet Frame
Addressing Let‘s send a letter from VM School to Helsinki School via Prague and Berlin. Frame is mailbag, Packet is envelope, Data is Letter. MAC Dest: Berlin Post Office, MAC Src: Prague Post Office IP Dest: Helsinki School, IP Src: VM School Letter Data Packet Frame
Addressing Letter Packet = Envelope with Letter remains always the same !!! • The frame is • - Secretary‘s bag between VM School and VM Post Office • - mailbag between VM and Prague • - another mailbag between Prague and Berlin • another mailbag between Berlin and Helsinki • Postman‘s bag between Helsinki Post Office and Helsinki School
Addressing Letter Packet = Envelope with Letter remains always the same !!!
Addressing Data = payload = what we want to transport Packet Frame
Addressing Let‘s ping from PC2 to PC1: ping 192.168.1.2
Addressing • Each PC, each interface has its own • IP address, • which can be changed • MAC address, • which cannot be changed
Addressing IP is always the same !!! Frame 1
Addressing IP is always the same !!! Frame 2
Addressing Frame 3 IP is always the same !!!
MAC Addressing • MAC address • burned into ROM permanently • cannot be changed • 48 bits • hexadecimal notation • example: 00:60:2F:3A:07:BC
MAC Addressing 48 bits
Summary • Frame • changes between „stations“ • Packet • stays always the same during its travel • IP address • 32 bits • dotted-decimal notation • „written“ on packet – doesn‘t change during transportation • logical – device‘s IP can be changed • MAC address • 48 bits • hexadecimal notation • „written“ on frame - changes during transportation • physical – device‘s MAC cannot be changed