Figure 4.1

R2

R1

H4

H5

H3H2H1

Network 2 (Ethernet)

Network 1 (Ethernet)

H6

Network 4(point-to-point)

H7 R3 H8

Network 3 (FDDI)

Figure 4.2

R1 R2 R3

H1 H8

ETH FDDI

IP

ETH

TCP

FDDI PPP PPP ETH

IP

ETH

TCP

IP IP IP

Figure 4.3

Version HLen TOS Length

Ident Flags Offset

TTL Protocol Checksum

SourceAddr

DestinationAddr

Options (variable) Pad(variable)

0 4 8 16 19 31

Data

Figure 4.4

H1 R1 R2 R3 H8

ETH FDDI

PPP IP (376)

PPP IP (512)

PPP IP (512) (512)

ETH IP

ETH IP

(512)ETH IP

(376)

IP (1400) IP (1400)

R1 R2 R3

Figure 4.5

(a)

Ident = x

Start of header

Rest of header

1400 data bytes

Offset = 00

(b)

Ident = x

Start of header

Rest of header

512 data bytes

Offset = 01

Ident = x

Rest of header

512 data bytes

Offset = 641

Start of header

Ident = x

Start of header

Rest of header

376 data bytes

Offset = 1280

Figure 4.6

Network Host

7 24

0(a)

Network Host

14 16

1 0(b)

Network Host

21 8

1 1 0(c)

Figure 4.7

Switchingfabric

Controlprocessor

Outputport

Inputport

Figure 4.8

TargetHardwareAddr (bytes 2 5)

TargetProtocolAddr (bytes 0 3)

SourceProtocolAddr (bytes 2 3)

Hardware type = 1 ProtocolType = 0x0800

SourceHardwareAddr (bytes 45)

TargetHardwareAddr (bytes 01)

SourceProtocolAddr (bytes 0 1)

HLen = 48 PLen = 32 Operation

SourceHardwareAddr (bytes 0― 3)

0 8 16 31

―

―

― ―

―

―

Figure 4.9

H2

H1

ATM network

10.0.0.210.0.0.1

12.0.0.3

12.0.0.5

R

LIS 10LIS 12

Figure 4.10

DHCPrelay

DHCPserver

Unicast to server

Broadcast

Host

Other networks

Figure 4.11

Operation HType HLen Hops

Xid

ciaddr

yiaddr

siaddr

giaddr

chaddr (16 bytes)

sname (64 bytes)

file (128 bytes)

options

Secs Flags

Figure 4.12

Corporation X private network

Corporation Y private network

Physical links

Physical links

Virtual circuits

(a)

(b)

C

A B

K L

M

K L

M

C

A B

Figure 4.13

IP header,Destination = 2.x

IP payload

IP header,Destination = 10.0.0.1

IP header,Destination = 2.x

IP payload

IP header,Destination = 2.x

IP payload

10.0.0.1

R1 R2InternetworkNetwork 1 Network 2

Figure 4.14

4

3

6

21

9

1

1D

A

FE

B

C

Figure 4.15

D

G

A

F

E

B

C

Figure 4.16

A

C

1

2

3

B

D

4

5

6

Figure 4.17

Address of net 2

Distance to net 2

Command Must be zero

Family of net 2 Address of net 2

Family of net 1 Address of net 1

Address of net 1

Distance to net 1

Version

0 8 16 31

Figure 4.18

(a)

X A

C B D

(b)

X A

C B D

(c)

X A

C B D

(d)

X A

C B D

Figure 4.19

D

A

B

C

5 3

211

10

Figure 4.20

Authentication

Version Type Message length

Checksum Authentication type

SourceAddr

AreaId

0 8 16 31

Figure 4.21

LS Age Options Type=1

0 Flags 0 Number of links

Link type Num_TOS Metric

Link-state ID

Advertising router

LS sequence number

Link ID

Link data

Optional TOS information

More links

LS checksum Length

Figure 4.22

225

140

907560

30

25% 50% 75% 100%

Utilization

9.6-Kbps satellite link

9.6-Kbps terrestrial link

56-Kbps satellite link

56-Kbps terrestrial link

Figure 4.23

Internetwork

Foreign agent(12.0.0.6)

Mobile host(10.0.0.9)

Home agent(10.0.0.3)

Home network(network 10)

Sending host

Figure 4.24

NSFNET backboneStanford

BARRNETregional

BerkeleyPARC

NCAR

UA

UNM

Westnetregional

UNL KU

ISU

MidNetregional■ ■ ■

Figure 4.25

Network number Host number

Class B address

Subnet mask (255.255.255.0)

Subnetted address

11111111111111111111111100000000

Network number Host IDSubnet ID

Figure 4.26

Subnet mask: 255.255.255.128Subnet number: 128.96.34.0

128.96.34.15128.96.34.1

H1 R1

128.96.34.130 Subnet mask: 255.255.255.128Subnet number: 128.96.34.128

128.96.34.129128.96.34.139

R2H2

128.96.33.1128.96.33.14

Subnet mask: 255.255.255.0Subnet number: 128.96.33.0

H3

Figure 4.27

Border gateway(advertises path to11000000000001)

Regional network

Corporation X(11000000000001000001)

Corporation Y(11000000000001000000)

Figure 4.28

R1

Autonomous system 1R2

R3

Autonomous system 2R4

R5 R6

Figure 4.29

Backbone service provider

Peeringpoint

Peeringpoint

Large corporation

Large corporation

Smallcorporation

“Consumer” ISP

“Consumer” ISP

“Consumer” ISP

Figure 4.30

Regional provider A(AS 2)

Regional provider B(AS 3)

Customer P(AS 4)

Customer Q(AS 5)

Customer R(AS 6)

Customer S(AS 7)

128.96192.4.153

192.4.32192.4.3

192.12.69

192.4.54192.4.23

Backbone network(AS 1)

Figure 4.31

0 15

Unfeasible routeslength

Withdrawn routes(variable)

Total pathattribute length

Path attributes(variable)

Network layerreachability info

(variable)

Figure 4.32

Area 1Area 0

Area 3

Area 2

R9

R8

R7

R1

R5R6

R4

R3

R2

Figure 4.33

125- m- n- o- pponm3

SubscriberIDProviderIDRegistryID010 InterfaceIDSubnetID

Figure 4.34

Version TrafficClass FlowLabel

PayloadLen NextHeader HopLimit

SourceAddress

DestinationAddress

0 4 12 16 24 31

Next header/data

Figure 4.35

NextHeader Reserved Offset RES M

Ident

0 8 16 29 31

Figure 4.36

R1 R2

R3 R4 R5

R6 R7

A

B

C

Figure 4.37

R7R6

R5R4

R2

R2

B

R6

R5R4

R1

R1

R1

A

C

R7

R6 R7

C

Source

Source

Source

R3

R5R4R3

R2

R3

C

B

A

A

B

Figure 4.38

RP

R3 R2 R4

R1 R5

(c)

RP

R3 R2 R4

R1 R5

(d)

RP

R3 R2 R4

R1 R5

(a)

RP

R3 R2 R4

R1 R5

(b)

Join

Join

Join

Join Join

Rendezvous pointRP =

Shared tree

Source-specific tree for source R1

Figure 4.39

RP

R3 R2 R4

R1 R5

Host

RP G

RP G

G

G

G

G

Figure 4.40

10.1.1/24

10.3.3/24

00

1

10.1.1 0

10.3.3 0■ ■ ■

Prefix Interface

10.1.1

10.3.3 0■ ■ ■

Prefix Interface

1

R2R1

R4

R3

Figure 4.41ab

10.1.1/24

10.3.3/24

00

1

R2R1

R4

R3

10.1.1 0

10.3.3 0■ ■ ■

Prefix Interface

15 10.1.1 1

16 10.3.3 0■ ■ ■

Label Prefix Interface

15 10.1.1 1

16 10.3.3 0■ ■ ■

Label Prefix Interface

Label = 15, Prefix = 10.1.1

10.1.1/24

10.3.3/2400

1

10.1.1 0

10.3.3 0■ ■ ■

Prefix Interface

R2R1

R4

R3

RemoteLabel

15

16

(a)

(b)

Figure 4.41c

(c)

10.1.1/24

10.3.3/24

00

1

R2R1

R4

R3

15 10.1.1 1 24

16 10.3.3 0■ ■ ■

Label Prefix Interface

10. 1.1 0

10. 3.3 0■ ■ ■

Prefix InterfaceRemoteLabel15

16

RemoteLabel

Label = 24, Prefix = 10.1.1

Figure 4.42

Label headerPPP header Layer 3 header

“ Shim“ header(for PPP, Ethernet,etc.)

ATM cellheader

HEC

Label

DATACLPPTIVCIGFC VPI(a)

(b)

Figure 4.43

R3 R4

R6

R5

R1

R2

LSR1

LSR2

LSR3

R3 R4

R6

R2

R1

R5

(a)

(b)

Figure 4.44

R1

R3

R2

R6

R4 R5

R7

Figure 4.45

R2

Tail

R3Head

ATM cells arrive

Cells sent intotunnel at head

Tunneled dataarrives at tail

ATM cells sent

Figure 4.46

R2

Tail

R3Head

1. ATM cells arrive6. ATM cells sent

101202

101DL

101DLTL

101DL

101DLTL

2. Demux label added

4. Packet is forwarded to tail3. Tunnel label added

5. Demux label examined

Figure 4.47

Providernetwork

VPN A /Site 3VPN A /Site 1

VPN A /Site 2

VPN B /Site 2

VPN B /Site 1

VPN B /Site 3

Figure 4.48

2

3

6

2

8 1

D

A

F

E

B

C

Figure 4.49

A B E

D C F

2 1

2 3

5 2 3

Figure 4.50

E A B

Figure 4.51

E A B

D

E A Band

Figure 4.52

A

C

B F G

Figure 4.53

A B C

D E5

5 4

1222

Figure 4.54

A D E

B C6

5 3

1131

Figure 4.55

A

B

C

Figure 4.56

A

1 2

3B

4Provider Q

Provider P

Provider R

Figure 4.57

Rest of Internet

A

C R1 RB R2 D

B

Figure 4.58

C

BA

Figure 4.59

R1

R2

R3 R4 R5

R6 R7

D

E

Figure 4.60

R1

S1

S2

R2

R4 R5

R6

R7

R8