Internet Routing How It Works

1
Internet RoutingHow It Works
Prepared and Presented by the NRO On Behalf of
the RIRs AfriNIC, APNIC, ARIN, LACNIC, RIPE NCC
2
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
(No Transcript)
4
(No Transcript)
5
(No Transcript)
6
(No Transcript)
7
(No Transcript)
8
(No Transcript)
9
6 ! / 2! ((6 2)!) 15
n! / p! ((n p)!) c
60 ! / 2! ((60 2)!) 1,770
600 ! / 2! ((600 2)!) 179,700
10
Network
11
Inter Connected Networks
12
Routed Internetwork
172.25.1.4
192.23.9.6
201.32.16.10
163.37.56.21
13
Using DNS
172.25.1.4
192.23.9.6
163.37.56.21
201.32.16.10
14
Administrative Grouping
172.25.1.4
192.23.9.6
201.32.16.10
163.37.56.21
15
Autonomous Systems
AS 2345
172.25.1.4
192.23.9.6
AS 1234
AS 3456
201.32.16.10
163.37.56.21
16
Routing Announcement
AS 2345
I speak for 172.25.1.0 and 201.32.16.0
172.25.1.4
192.23.9.6
AS 1234
AS 3456
201.32.16.10
163.37.56.21
17
Policy Announcement
AS 2345
I prefer AS2345 but not AS3456
172.25.1.4
192.23.9.6
AS 1234
AS 3456
201.32.16.10
163.37.56.21
18
Policy Announcement
AS 2345
I refuse AS3456
172.25.1.4
192.23.9.6
AS 1234
AS 3456
201.32.16.10
163.37.56.21
19
Thank You