PPT: Internetworking | Computer Networks - Computer Science Engineering (CSE) PDF Download

 Page 1


1
1
Internetworking
2
4.1 Simple Internetworking (IP)
4.1.1 What is an Internework
4.1.2 Service Model
4.1.3 Global Address
4.1.4 Datagram Forwarding in IP
4.1.5 Address Translation (ARP)
4.1.6 Host Configuration (DHCP)
4.1.7 Error Reporting (ICMP)
4.1.8 Virtual Networks and Tunnels
Page 2


1
1
Internetworking
2
4.1 Simple Internetworking (IP)
4.1.1 What is an Internework
4.1.2 Service Model
4.1.3 Global Address
4.1.4 Datagram Forwarding in IP
4.1.5 Address Translation (ARP)
4.1.6 Host Configuration (DHCP)
4.1.7 Error Reporting (ICMP)
4.1.8 Virtual Networks and Tunnels
2
3
4.1.1 What is an Internework
o Concatenation of networks
R2
R1
H4
H5
H3 H2 H1
Network 2 (Ethernet)
Network 1 (Ethernet)
H6
Network 4
(point-to-point)
H7 R3 H8
Network 3 (FDDI)
A simple internetwork. H
n
=host, R
n
= router
4
o An internetwork is a network of networks
n in the figure, we see Ethernets, an FDDI ring, and a
point-to-point link
n each of these is a single-technology network
n the nodes that interconnect the networks are called
routers (sometimes called gateways)
o The following figure shows how H1 and H8 are
logically connected by the internet, including
the protocol graph running on each node
Page 3


1
1
Internetworking
2
4.1 Simple Internetworking (IP)
4.1.1 What is an Internework
4.1.2 Service Model
4.1.3 Global Address
4.1.4 Datagram Forwarding in IP
4.1.5 Address Translation (ARP)
4.1.6 Host Configuration (DHCP)
4.1.7 Error Reporting (ICMP)
4.1.8 Virtual Networks and Tunnels
2
3
4.1.1 What is an Internework
o Concatenation of networks
R2
R1
H4
H5
H3 H2 H1
Network 2 (Ethernet)
Network 1 (Ethernet)
H6
Network 4
(point-to-point)
H7 R3 H8
Network 3 (FDDI)
A simple internetwork. H
n
=host, R
n
= router
4
o An internetwork is a network of networks
n in the figure, we see Ethernets, an FDDI ring, and a
point-to-point link
n each of these is a single-technology network
n the nodes that interconnect the networks are called
routers (sometimes called gateways)
o The following figure shows how H1 and H8 are
logically connected by the internet, including
the protocol graph running on each node
3
5
o A simple internetwork of protocol stack
R1 R2 R3
H1 H8
ETH FDDI
IP
ETH
TCP
FDDI PPP PPP ETH
IP
ETH
TCP
IP IP IP
Protocol layers used to connect H1 to H8.
ETH: the protocol that runs over Ethernet.
6
4.1.2 Service Model
o A good place to start when you build an internetwork
is to define its service model
o A service model is the host-to-host services you want
to provide
o Service model for an internetwork
n a host-to-host service only if this service can
somehow be provided over each of the underlying
physical networks
Page 4


1
1
Internetworking
2
4.1 Simple Internetworking (IP)
4.1.1 What is an Internework
4.1.2 Service Model
4.1.3 Global Address
4.1.4 Datagram Forwarding in IP
4.1.5 Address Translation (ARP)
4.1.6 Host Configuration (DHCP)
4.1.7 Error Reporting (ICMP)
4.1.8 Virtual Networks and Tunnels
2
3
4.1.1 What is an Internework
o Concatenation of networks
R2
R1
H4
H5
H3 H2 H1
Network 2 (Ethernet)
Network 1 (Ethernet)
H6
Network 4
(point-to-point)
H7 R3 H8
Network 3 (FDDI)
A simple internetwork. H
n
=host, R
n
= router
4
o An internetwork is a network of networks
n in the figure, we see Ethernets, an FDDI ring, and a
point-to-point link
n each of these is a single-technology network
n the nodes that interconnect the networks are called
routers (sometimes called gateways)
o The following figure shows how H1 and H8 are
logically connected by the internet, including
the protocol graph running on each node
3
5
o A simple internetwork of protocol stack
R1 R2 R3
H1 H8
ETH FDDI
IP
ETH
TCP
FDDI PPP PPP ETH
IP
ETH
TCP
IP IP IP
Protocol layers used to connect H1 to H8.
ETH: the protocol that runs over Ethernet.
6
4.1.2 Service Model
o A good place to start when you build an internetwork
is to define its service model
o A service model is the host-to-host services you want
to provide
o Service model for an internetwork
n a host-to-host service only if this service can
somehow be provided over each of the underlying
physical networks
4
7
4.1.2 Service Model
o IP service model has two parts
n addressing scheme
o provides a way to identify all hosts in the internetwork
n datagram (conectionless) model of data delivery
o This service model is sometimes called best effort
n although IP makes every effort to deliver datagrams, it makes
no guarantees
8
o Datagram
n a type of packet sent in a connectionless manner
over a network
n every datagram carry enough information to let
the network forward the packet to its correct
destination
n no need for any advance setup mechanism to tell
the network what to do when the packet arrives
Page 5


1
1
Internetworking
2
4.1 Simple Internetworking (IP)
4.1.1 What is an Internework
4.1.2 Service Model
4.1.3 Global Address
4.1.4 Datagram Forwarding in IP
4.1.5 Address Translation (ARP)
4.1.6 Host Configuration (DHCP)
4.1.7 Error Reporting (ICMP)
4.1.8 Virtual Networks and Tunnels
2
3
4.1.1 What is an Internework
o Concatenation of networks
R2
R1
H4
H5
H3 H2 H1
Network 2 (Ethernet)
Network 1 (Ethernet)
H6
Network 4
(point-to-point)
H7 R3 H8
Network 3 (FDDI)
A simple internetwork. H
n
=host, R
n
= router
4
o An internetwork is a network of networks
n in the figure, we see Ethernets, an FDDI ring, and a
point-to-point link
n each of these is a single-technology network
n the nodes that interconnect the networks are called
routers (sometimes called gateways)
o The following figure shows how H1 and H8 are
logically connected by the internet, including
the protocol graph running on each node
3
5
o A simple internetwork of protocol stack
R1 R2 R3
H1 H8
ETH FDDI
IP
ETH
TCP
FDDI PPP PPP ETH
IP
ETH
TCP
IP IP IP
Protocol layers used to connect H1 to H8.
ETH: the protocol that runs over Ethernet.
6
4.1.2 Service Model
o A good place to start when you build an internetwork
is to define its service model
o A service model is the host-to-host services you want
to provide
o Service model for an internetwork
n a host-to-host service only if this service can
somehow be provided over each of the underlying
physical networks
4
7
4.1.2 Service Model
o IP service model has two parts
n addressing scheme
o provides a way to identify all hosts in the internetwork
n datagram (conectionless) model of data delivery
o This service model is sometimes called best effort
n although IP makes every effort to deliver datagrams, it makes
no guarantees
8
o Datagram
n a type of packet sent in a connectionless manner
over a network
n every datagram carry enough information to let
the network forward the packet to its correct
destination
n no need for any advance setup mechanism to tell
the network what to do when the packet arrives
5
9
o Best-effort delivery (unreliable service)
n if something goes wrong and has the following
situations
o packets are lost
o packets are delivered out of order
o duplicate copies of a packet are delivered
o packets can be delayed for a long time
n the network does not make any attempt to recover
from the failure
o Best-effort, connectionless service is about the
simplest service you could ask for from an
internetwork
o If you provide best-effort service over a
network that provides a reliable service, then
that’s fine
10