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Drumming up more addresses on the Internet LCI Department English B2 Oral Exam Student: Julian GARBISO
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Drumming up more
addresses on the Internet
LCI Department
English B2 Oral Exam
Student: Julian GARBISO
8/3/2019 Drumming Up More Addresses on the Internet
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Julian GARBISO English B2 Oral Exampage 1
How do we communicate over the Internet?
OSI model
Levels 2, 3 and 4 headers
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page 2
OSI Model
Designed by ISO
Describes how a communication system¶s
structure should be
Structured in terms of abstraction layers
It is a concept far more general than the Internet
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OSI Model: Internet
Application
Presentation
Session
Transport
Network
Data Link
Physical
HTTP, FTP, «
TCP
IP
MAC, LLC, «
Ethernet, «
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page 5
OSI Model: Internet
DataTCPIPMAC CRCEthernet
Structure of a complete frame
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The problem concerning theaddresses
In the beginning«
IPv4 addresses
Patches: NAT
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page 7
In the beginning«
May 1974: IEEE paper " A Protocol for Packet
Network Interconnection" (Vint Cerf, Bob Kahn)
Conception of TCP/IP
They determined that IP addresses would be 32-bit
long
IETF RFC 791 (September 1981): IPv4
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IPv4 addresses
32 bits, divided into 4 octets (bytes)
1000 0011 1111 1110 0110 0100 0011 0000
131 . 254 . 100 . 48
4.3 billion possible addresses
However, some of them are reserved (private networks, multicast addresses)
There are nearly 7 billion people in the world
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page 9
Temporary solutions: NAT
Network Address and Port Translation
The private network uses the IP address
blocks reserved for that purpose:
10.0.0.0 to 10.255.255.255
172.16.0.0 to 172.31.255.255
192.168.0.0 to 192.168.255.255
The NAT Router has the only public IP
address.
The NAT Router manages a table in which
it stores the correspondence between
private IP address and port and the public
port used for each flux.
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IPv6
IPv6 addresses
Comparison of magnitudes
IPv6 advantages
Transition protocols
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IPv6 addresses
128 bits
3.4×1038 possible addresses
Zeros at the end can be omitted
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Comparison between magnitudes
IPv4
4 billionaddresses
1 IP address for only half the
population of the Earth
IPv6
3.4×1038
addresses
1 IP address for every single
grain of sand in the Earth,
including deserts and under-
sea sand.
«340 billion times.
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page 13
Transition protocols
6rd
4rd
6to4
«
In general, these are tunneling mechanisms.
A tunneling protocol is used to encapsulate apayload protocol in a delivery protocol (often due to
incompatibility or security reasons).
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IPv6 advantages
Larger address spaceallows
Global reachability
Multihoming
Autoconfiguration
No need for NAT
Mobility and security Mobile IP RFC-compliant IPsec is native in IPv6
Simpler header Routing efficiency
Scalability
No checksums
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page 15
Questions?
Julian GARBISO English B2 Oral Exam
