Capitolo 7
I protocolli di trasporto e di servizio della
famiglia TCP/IP
Copyright © 2002 - The McGraw-Hill Companies srl
Porta numero
2523
Porta numero
4322
Copyright © 2002 - The McGraw-Hill Companies srl
32 bit
Source Port
Destination Port
Sequence Number
Acknowledgement Number
HLEN Reser.
Code
Bits
Checksum
Options
Window
Urgent Pointer
PAD
Copyright © 2002 - The McGraw-Hill Companies srl
130.192.3.29
130.192.5.33
2351
SYN,SN=18421174

SYN,ACK,SN=1249155681,AN=18421175

SYN,ACK,SN=18421175,AN=1249155682
Client
80

Server
AN: Acknowledgment
Number
SN: Sequence Number
Copyright © 2002 - The McGraw-Hill Companies srl
130.192.5.33
FIN,ACK,SN=2541997339,AN=41635320

4549

Client
AN:
 130.192.2.53
FIN,SN=41635319
FIN,SN=2541997339,AN=41635320
FIN,ACK,SN=41635320,AN=2541997340
Acknowledgment
Number
SN: Sequence
Number
110
 Server
Copyright © 2002 - The McGraw-Hill Companies srl
Finestra di trasmissione
3 4
8
11
18
30
Byte trasmesso di cui è nota l’avvenuta consegna
Byte trasmesso sulla cui consegna non si hanno informazioni
Byte non ancora trasmesso
Byte non ancora trasmissibile
Finestra di trasmissione dopo la ricezione
di un messaggio con Acknowledgment
Number=11
3 4
8
11
18
30
Copyright © 2002 - The McGraw-Hill Companies srl
Root
edu
il
it
com
edu
ucla
njit
polito
www
netgroup
pop
it
com
polito
cnr
eni
gs
cnn
kodak
bn
eni
www
ftp
mail
il
ac
co
mi
ac
haifa
technion
co
lynx
icq
Copyright © 2002 - The McGraw-Hill Companies srl
Root
ftp.technion.ac.il?
8
edu
il
it
com
ftp.technion.ac.il?
3
9
it
com
gs
cnn
kodak
bn
polito
cnr
eni
polito
2
www
1
netgroup
pop
il
ac
co
mi
eni
ac
7
co
haifa
technion
www
ftp
mail
4
lynx
icq
technion
10
6
tilie.polito.it
5
www
ftp
mail
Copyright © 2002 - The McGraw-Hill Companies srl
DHCP Client
Ho bisogno di
configurazione
Ecco il tuo
indirizzo,
netmask ...
DHCP Server
Base dati di
indirizzi IP
Copyright © 2002 - The McGraw-Hill Companies srl
000102-0CF9AA
195.31.235.220
00D0B7-4D9EB3
DHCPdiscover 
 DHCPoffer
DHCPrequest
192.168.10.105


DHCPack
Copyright © 2002 - The McGraw-Hill Companies srl
WAN
(routing dinamico su rete magliata)
Router X
10.1.1.1
Router Y
HSRP Group 24
Host 10.1.1.10
Def. GTW 10.1.1.5
10.1.1.2
Host 10.1.1.24
Def. GTW 10.1.1.5
Router-X> interface ethernet 0
Router-X> Ip address 10.1.1.1 255.255.255.0
Router-X> standby 24 ip 10.1.1.5
Router-Y> interface ethernet 0
Router-Y> Ip address 10.1.1.2 255.255.255.0
Router-Y> standby 24 ip 10.1.1.5
Copyright © 2002 - The McGraw-Hill Companies srl
WAN
(routing dinamico su rete magliata)
Router X
Active
10.1.1.1
10.1.1.5
Router Y
Standby
HSRP Group 24
Host 10.1.1.10
Def. GTW 10.1.1.5
Router-X>
Router-X>
Router-X>
Router-X>
Router-X>
10.1.1.2
Host 10.1.1.24
Def. GTW 10.1.1.5
interface ethernet 0
Ip address 10.1.1.1 255.255.255.0
standby 24 preempt
standby 24 priority 105
standby 24 ip 10.1.1.5
Router-Y>
Router-Y>
Router-Y>
Router-Y>
interface ethernet 0
Ip address 10.1.1.2 255.255.255.0
standby 24 preempt
standby 24 ip 10.1.1.5
Copyright © 2002 - The McGraw-Hill Companies srl
Router Z
S0=10.6.2.5
S0=10.6.7.6
Router X
Active
10.1.1.5
10.1.1.10
Host 10.1.1.28
Def. GTW 10.1.1.10
Router Y
Standby
HSRP Group 1
Host 10.1.1.24
Def. GTW 10.1.1.10
R-X>interface ethernet 0
R-X-if>Ip address 10.1.1.5 255.255.255.0
R-X-if>standby 1 preempt
R-X-if>standby 1 priority 105
R-X-if>standby 1 ip 10.1.1.10
R-X-if>standby 1 track Serial 0
R-X-if>no shutdown
R-X-if>exit
R-X> interface serial 0
R-X-if>Ip address 10.6.2.5 255.255.255.0
10.1.1.6
Host 10.1.1.25
Def. GTW 10.1.1.10
Host 10.1.1.31
Def. GTW 10.1.1.10
R-Y>interface ethernet 0
R-Y-if>Ip address 10.1.1.6 255.255.255.0
R-Y-if>standby 1 preempt
R-Y-if>standby 1 ip 10.1.1.10
R-Y-if>standby 1 track Serial 0
R-Y-if>no shutdown
R-Y-if>exit
R-Y> interface serial 0
R-Y-if>Ip address 10.6.7.6 255.255.255.0
Copyright © 2002 - The McGraw-Hill Companies srl
Router Z
S0=10.6.2.5
10.1.1.5
10.1.1.10
Host 10.1.1.28
Def. GTW 10.1.1.10
S0=10.6.7.6
Router X
Active 1
Standby 2
Router Y
Active 2
Standby 1
HSRP Group 1
HSRP Group 2
Host 10.1.1.24
Def. GTW 10.1.1.10
R-X>interface ethernet 0
R-X-if>Ip address 10.1.1.5 255.255.255.0
R-X-if>standby 1 preempt
R-X-if>standby 1 ip 10.1.1.10
R-X-if>standby 1 track Serial 0
R-X-if>standby 2 preempt
R-X-if>standby 2 ip 10.1.1.20
R-X-if>standby 2 track serial 0
R-X-if>standby 2 priority 95
10.1.1.6
10.1.1.20
Host 10.1.1.205
Def. GTW 10.1.1.20
Host 10.1.1.206
Def. GTW 10.1.1.20
R-Y>interface ethernet 0
R-Y-if>Ip address 10.1.1.6 255.255.255.0
R-Y-if>standby 1 preempt
R-Y-if>standby 1 ip 10.1.1.10
R-Y-if>standby 1 track Serial 0
R-Y-if>standby 1 priority 95
R-Y-if>standby 2 preempt
R-Y-if>standby 2 ip 10.1.1.20
R-Y-if>standby 2 track serial 0
Copyright © 2002 - The McGraw-Hill Companies srl
HEADER
MAC
HEADER
IP
HEADER
UDP
Pacchetto HSRP
FCS
Version
Op Code
State
Hello-time
Hold-time
Priority
Group
Reserved
Authentication Data
Authentication Data
Virtual IP Address
Copyright © 2002 - The McGraw-Hill Companies srl
HEADER HEADER
MAC
IP
Pacchetto VRRP
Vers = 2 Type = 1 Virtual Router ID
Auth Type
FCS
Priority
Advers Interval
Count Ip Addrs
Checksum
Virtual IP Address 1
..
.
Virtual IP Address n
Authentication Data (1)
Authentication Data (2)
Copyright © 2002 - The McGraw-Hill Companies srl
WAN
(routing dinamico su rete magliata )
Router X
Master o
Active
Router Y
Backup o
Standby
Copyright © 2002 - The McGraw-Hill Companies srl
WAN
(routing dinamico su rete magliata )
Router X
Init
Router Y
Master o
Active
guasto
Copyright © 2002 - The McGraw-Hill Companies srl
WAN
(routing dinamico su rete magliata )
Router X
Master o
Active
Router Y
Init
guasto
Copyright © 2002 - The McGraw-Hill Companies srl
WAN
(routing dinamico su rete magliata )
Router X
Master o
Active
Router Y
Master o
Active
guasto
Copyright © 2002 - The McGraw-Hill Companies srl
WAN
(routing dinamico su rete magliata )
Router X
Master o
Active
Router Y
Backup o
Standby
RSTP/STP
Copyright © 2002 - The McGraw-Hill Companies srl