شابتر 1.pdf - Chapter 4 Network Layer (IP and Routing...

Chapter 4
Network Layer
(IP and Routing Protocols)
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All material copyright 1996-2009
J.F Kurose and K.W. Ross, All Rights Reserved
Computer Networking:
A Top Down Approach
5
th
edition.
Jim Kurose, Keith Ross
Addison-Wesley, April
2009.
IP and Routing Protocols 4-1

Chapter 4: Network Layer
Chapter goals:
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understand principles behind network layer
services:
m
Network layer service models
m
Forwarding versus routing
m
IPv4 addressing
m
NAT
m
IPv4 Vs. IPv6
m
Routing protocols
IP and Routing Protocols 4-2

Chapter 4: Network Layer
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4. 1 Introduction
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4.2 Virtual circuit and
datagram networks
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4.3 What’s inside a
router
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4.4 IP: Internet
Protocol
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Datagram format
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IPv4 addressing
m
ICMP
m
IPv6
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4.5 Routing algorithms
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Link state
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Distance Vector
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Hierarchical routing
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4.6 Routing in the
Internet
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RIP
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OSPF
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BGP
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4.7 Broadcast and
multicast routing
IP and Routing Protocols 4-3

Network layer
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transport segment from sending to
receiving host
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ﻧ ﻘ ل ا ﻟ ﻣ ﻘ ط ﻊ ﻣ ن ا ﻹ ر ﺳ ﺎ ل إ ﻟ ﻰ ا ﻟ ﻣ ﺿ ﯾ ف ا ﻟ ﻣ ﺳ ﺗ ﻘ ﺑ
ِ
ل
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on sending side encapsulates segments
into datagrams
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ﻋ ﻧ د إ ر ﺳ ﺎ ل ا ﻟ ﺟ ﺎ ﻧ ب ﯾ ﻘ و م ﺑ ﺗ ﺿ ﻣ ﯾ ن ا ﻟ ﻣ ﻘ ﺎ ط ﻊ ﻓ ﻲ ﻣ ﺧ ط ط ﺎ ت
ا ﻟ ﺑ ﯾ ﺎ ﻧ ﺎ ت
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on rcving side, delivers segments to
transport layer
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ﻋ ﻠ ﻰ ا ﻟ ﺟ ﺎ ﻧ ب ا ﻟ ﻣ ﺗ ﺟ و ل ، ﯾ ﻘ و م ﺑ ﺗ و ﺻ ﯾ ل ا ﻟ ﻣ ﻘ ﺎ ط ﻊ إ ﻟ ﻰ ط ﺑ ﻘ ﺔ ا ﻟ ﻧ ﻘ ل
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network layer protocols in every host,
router
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ﺑ ر و ﺗ و ﻛ و ﻻ ت ط ﺑ ﻘ ﺔ ا ﻟ ﺷ ﺑ ﻛ ﺔ ﻓ ﻲ ﻛ ل ﻣ ﺿ ﯾ ف ، ﺟ ﮭ ﺎ ز ﺗ و ﺟ ﯾ ﮫ
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router examines header fields in all IP
datagrams passing through it
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ﯾ ﻘ و م ﺟ ﮭ ﺎ ز ا ﻟ ﺗ و ﺟ ﯾ ﮫ ﺑ ﻔ ﺣ ص ﺣ ﻘ و ل ا ﻟ ر أ س ﻓ ﻲ ﻛ ﺎ ﻓ ﺔ ﻣ ﺧ ط ط ﺎ ت
ﺑ ﯾ ﺎ ﻧ ﺎ ت IP ا ﻟ ﺗ ﻲ ﺗ ﻣ ر ﻣ ن ﺧ ﻼ ﻟ ﮭ ﺎ ھ و
application
transport
data link
physical
application
transport
network
data link
physical
network
data link
physical
network
data link
physical
network
data link
physical
network
data link
physical
network
data link
physical
network
data link
physical
network
data link
physical
network
data link
physical
network
data link
physical
network
data link
physical
network
data link
physical
IP and Routing Protocols 4-4

Two Key Network-Layer Functions
و ظ ﯾ ﻔ ﺗ ﺎ ن أ ﺳ ﺎ ﺳ ﯾ ﺗ ﺎ ن ﻟ ط ﺑ ﻘ ﺔ ا ﻟ ﺷ ﺑ ﻛ ﺔ
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forwarding: move packets from
router’s input to appropriate router
output
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إ ﻋ ﺎ د ة ا ﻟ ﺗ و ﺟ ﯾ ﮫ : ﻧ ﻘ ل ا ﻟ ﺣ ز م ﻣ ن إ د ﺧ ﺎ ل ﺟ ﮭ ﺎ ز ا ﻟ ﺗ و ﺟ ﯾ ﮫ إ ﻟ ﻰ
إ ﺧ ر ا ج ﺟ ﮭ ﺎ ز ا ﻟ ﺗ و ﺟ ﯾ ﮫ ا ﻟ ﻣ ﻧ ﺎ ﺳ ب
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routing: determine route taken by