文档介绍：Chapter 4-work layer
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Network layer
Chapter 4: Network Layer
Chapter goals:
understand principles work layer services:
network layer service models
forwarding versus routing
how a router works
routing (path selection)
dealing with scale
advanced topics: IPv6, mobility
instantiation, implementation in the
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Network layer
Chapter 4: Network Layer
4. 1 Introduction
Virtual circuit and works
What’s inside a router
IP: Protocol
Datagram format
IPv4 addressing
VLSM/CIDR
ICMP
IPv6
IP sec
Routing algorithms
Link state
Distance Vector
Hierarchical routing
Routing in the
RIP
OSPF
BGP
Broadcast and multicast routing
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Network layer
Chapter 4: Network Layer
4. 1 Introduction
Virtual circuit and works
What’s inside a router
IP: Protocol
Datagram format
IPv4 addressing
ICMP
IPv6
Routing algorithms
Link state
Distance Vector
Hierarchical routing
Routing in the
RIP
OSPF
BGP
Broadcast and multicast routing
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Network layer
Network layer
transport segment from sending to receiving host
on sending side encapsulates segments into datagrams
on rcving side, delivers segments to transport work layer protocols in every host, router
router examines header fields in all IP datagrams passing through it
application
work
data link
physical
application
work
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
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Network layer
Two work-Layer Functions
forwarding: move packets from router’s input to appropriate router output
routing: determine route taken by packets from source to dest.
routing algorithms
analogy:
routing: process of planning trip from source to dest
forwarding: process of getting through single interchange
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Network layer
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