1. Internet Routing How It Works Prepared and Presented by the NRO On Behalf of the RIRs AfriNIC, APNIC, ARIN, LACNIC, RIPE NCC

2. Routing – How It WorksGovernment Advisory CommitteeJuly 2005 Definitions Routing The act of moving information across an internetwork from a source to a destination. Domain Name System [DNS] A means of storing and retrieving information about hostnames and IP addresses in a distributed data base.

3. Point-to-Point Networking Routing – How It WorksGovernment Advisory CommitteeJuly 2005

4. Point-to-Point Networking Routing – How It WorksGovernment Advisory CommitteeJuly 2005

5. Point-to-Point Networking Routing – How It WorksGovernment Advisory CommitteeJuly 2005

6. Point-to-Point Networking Routing – How It WorksGovernment Advisory CommitteeJuly 2005

7. Point-to-Point Networking Routing – How It WorksGovernment Advisory CommitteeJuly 2005

8. Point-to-Point Networking Routing – How It WorksGovernment Advisory CommitteeJuly 2005

9. Point-to-Point Networking Routing – How It WorksGovernment Advisory CommitteeJuly 2005 6 ! / 2! * ((6 – 2)!) = 15n! / p! * ((n – p)!) = c 60 ! / 2! * ((60 – 2)!) = 1,770 600 ! / 2! * ((600 – 2)!) = 179,700

10. Routing – How It WorksGovernment Advisory CommitteeJuly 2005 Network

11. Routing – How It WorksGovernment Advisory CommitteeJuly 2005 Inter Connected Networks

12. Routing – How It WorksGovernment Advisory CommitteeJuly 2005 Routed Internetwork 172.25.1.4 192.23.9.6 201.32.16.10163.37.56.21

13. Routing – How It WorksGovernment Advisory CommitteeJuly 2005 Using DNS 172.25.1.4 192.23.9.6 201.32.16.10 163.37.56.21

14. Routing – How It WorksGovernment Advisory CommitteeJuly 2005 Administrative Grouping 172.25.1.4 192.23.9.6 201.32.16.10 163.37.56.21

15. Routing – How It WorksGovernment Advisory CommitteeJuly 2005 Autonomous Systems 172.25.1.4 192.23.9.6 201.32.16.10 163.37.56.21 AS 1234 AS 2345 AS 3456

16. Routing – How It WorksGovernment Advisory CommitteeJuly 2005 Routing Announcement 172.25.1.4 192.23.9.6 201.32.16.10 163.37.56.21 AS 1234 AS 2345 AS 3456 I speak for 172.25.1.0 and 201.32.16.0

17. Routing – How It WorksGovernment Advisory CommitteeJuly 2005 Policy Announcement 172.25.1.4 192.23.9.6 201.32.16.10 163.37.56.21 AS 1234 AS 2345 AS 3456 I prefer AS2345 but not AS3456

18. Routing – How It WorksGovernment Advisory CommitteeJuly 2005 Policy Announcement 172.25.1.4 192.23.9.6 201.32.16.10 163.37.56.21 AS 1234 AS 2345 AS 3456 I refuse AS3456

19. Routing – How It WorksGovernment Advisory CommitteeJuly 2005