2. ICC Module 3 Lesson 4 – Networking 1 / 9 © 2015 Ph. Janson Information, Computing & Communication Networking – Clip 6 – Internet addressing School of Computer Science & Communications Ph. Janson

3. ICC Module 3 Lesson 4 – Networking 2 / 9 © 2015 Ph. Janson Outline ►Computer communication basics  Clip 1 – Protocols & messages Clip 1  Clip 2 – Protocol layers Clip 2  Clip 3 – Protocol encapsulation Clip 3  Clip 4 – Switching Clip 4 ►Internet basics  Clip 5 – Internet topology & interfaces Clip 5  Clip 6 – Internet addressing & routing Clip 6  Clip 7 – Internet route calculation Clip 7  Clip 8 – Internet protocols Clip 8 ►Computer network paradigms  Clip 9 – Network paradigms Clip 9 Intro clipPrevious clipNext clip

4. ICC Module 3 Lesson 4 – Networking 3 / 9 © 2015 Ph. Janson Addressing ►Every computer has a unique IP address  Two versions: IPv4: 32 bits - 2 32 (~4.10 9 ) computers interpreted as SN.A = computer A (24-8 bits) on subnetwork SN (8-24 bits) IPv6: 128 bits - 2 128 (~256.10 9.10 9.10 9.10 9 ) computers ►Every IP packet header contains the IP addresses of its source and destination computers Routing ►How can packets be passed along the ‘shortest’ route from source to destination ? ►Every router contains a routing table indicating  The direction (next hop) towards every possible destination  The distance (hop count) to every possible destination Layer 3 – IP addressing & routing

5. ICC Module 3 Lesson 4 – Networking 4 / 9 © 2015 Ph. Janson A A B B C C D D E E Layer 3 – IP routing example

6. ICC Module 3 Lesson 4 – Networking 5 / 9 © 2015 Ph. Janson A A B B C C D D E E destdirectiondistance BD2 CC1 DD1 EE1 Layer 3 – IP routing table example (A)

7. ICC Module 3 Lesson 4 – Networking 6 / 9 © 2015 Ph. Janson A A B B C C D D E E destdirectiondistance AA1 BB1 CA/E2 EE1 Layer 3 – IP routing table example (D)

8. ICC Module 3 Lesson 4 – Networking 7 / 9 © 2015 Ph. Janson destdirectiondistance AA1 BA/E3 D 2 EE1 A A B B C C D D E E Layer 3 – IP routing table example (C)

9. ICC Module 3 Lesson 4 – Networking 8 / 9 © 2015 Ph. Janson A A B B C C D D E E destdirectiondistance BD2 CC1 DD1 EE1 Layer 3 – IP routing example from A to B (1)

10. ICC Module 3 Lesson 4 – Networking 9 / 9 © 2015 Ph. Janson A A B B C C D D E E destdirectiondistance AA1 BB1 CA/E2 EE1 Layer 3 – IP routing example from A to B (2)