about ip addresses. 193.0.0.131 196.216.2.1 192.149.252.7 200.160.2.15 202.12.29.20 192.0.0.214...
TRANSCRIPT
About IP Addresses
193.0.0.131
196.216.2.1
192.149.252.7
200.160.2.15
202.12.29.20
192.0.0.214
206.131.253.68
192.0.34.163
www.nro.net
www.afrinic.net
www.arin.net
www.lacnic.net
www.apnic.net
www.ripe.net
www.isoc.org
www.icann.org
On the Internet, you are nothing but an IP address!
202.12.29.142
What is an IP Address?
An Internet Protocol (IP) address is a numeric identifier that
includes information about how to reach a network location
through the Internet routing system.
IPv4 and IPv6
Internet Protocol version 4
Internet Protocol version 6
32-bit* number 128-bit* number
Dotted Decimal Notation:192.0.2.0
Hexadecimal Notation:2001:DB8::/32
4 billion network addresses
16 billion-billion network addresses
* bit = binary digit
IP Addresses Are:
• Necessary for Internet routing
• A finite common resource
• Not dependent upon the DNS
• Not “owned” by address users
– Not property
– Cannot be bought, sold, traded…
– Provided on a temporary basis
– Returned to registry or provider when no longer required
IP Addresses Are:
How does an IP address make the
Internet work?
What is Routing?
Routing is the act of moving information across an
internetwork from a source to a destination.
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Each computer communicates with the other computers on its network, creating a total of 15 connections.
Six computers need to communicate with each other.
On a larger network, individual connections become unmanageable.
Point-to-Point Networking
Network
Instead, the computers can connect to a single router. ``
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Router
Interconnected Networks
Each network can link to other networks via its router.
172.25.1.4 192.23.9.6
201.32.16.10
Each segment receives IP addresses.
163.37.56.21
172.25.1.4 192.23.9.6
201.32.16.10 163.37.56.21
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Administrative Grouping
Registries provide Internet number resources to help divide internetworks into interconnected, autonomous groups of devices.
172.25.1.4 192.23.9.6
201.32.16.10
163.37.56.21
AS 1234 AS 2345
AS 3456
Groups of devices with a single, clearly defined routing policy may be assigned an Autonomous System Number (ASN).
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Traffic202.12.29.0/24 Announce202.12.29.0/24
Internet Address Routing
Internetwork Routing Table
4.128/9
60.100/16
60.100.0/20
135.22/16
…
Internetwork Routing Table
4.128/9
60.100/16
60.100.0/20
135.22/16
202.12.29.0/24…
202.12.29.0/24
1. The network announces an IP address range.
2. The range is added to a specific table within a router.
3. The router can redistribute information to devices within the network.
The Internet
Internet Address Routing
Traffic202.12.29.142
Routing Table
202.12.29.0/25
202.12.29.128/25Local Router
202.12.29.142
202.12.29.0/24
1. Traffic enters the network according to the routing table.
2. The local router directs traffic to the appropriate device according to its own routing table.
Global Internet Routing
Network
Network
Network
Network
Network
Network
Network
Network
Network
Network
Network
Internetwork Routing Table
4.128/9
60.100/16
60.100.0/20
135.22/16
…With a coordinated numbering system, you can build a network of networks.
What is the Domain Name System (DNS)?
The Domain Name System (DNS) is a means of storing and
retrieving information about host names and IP addresses in a
distributed database.
IP Addresses Are Not Domain Names
IP Address Domain Name
Computer-friendly People-friendly
Identifier Reference
Unique number identifies computer on Internet
Host name mapped to an IP address
Used for routing Not used for routing
2001:0C00:8888::My Computer www. cernet.cn
2001:0400::
www.cernet.cn? 202.112.0.462001:0400::
Using Domain Names
The Internet
DNS
1. My Computer asks the DNS where to find www.cernet.cn
2. The DNS provides the IPv4 or IPv6 address for the requested URL.
3. My Computer queries the appropriate server for the IP address provided by the DNS.
