1. Delivering the Data

2. Nội dung Addressing, Routing, and Multiplexing IP Address
Internet Routing Architecture
Routing Table
Protocols, Ports, and Sockets

3. Addressing, Routing,Multiplexing
TCP/IP uses 3 schemes to accomplish these tasks
Addressing
IP addresses, which uniquely identify every host on the network, deliver data to the correct host.
Routing
Gateways deliver data to the correct network.
Multiplexing
Protocol and port numbers deliver data to the correct software module within the host.

4. IP Address
32-bit value that uniquely identifies every device attached to TCP/IP Internet
4 decimal numbers separated by dots
assigned to network interfaces, not to computer systems
Systems can be addressed in 3 way
unicast address
individual host
multicast address
Groups of systems,
broadcast address
All systems on a network , IP address with all host bits set to 1

5. IP Address
An IP address with all host bits set to 0 identifies network itself
refers to network
Network addresses with a first byte value greater than 223 cannot be assigned to physical network
default route
Network
loopback address
network
allowing the local host to be addressed in the same manner as a remote host

6. Address Structure IP address contains network part (prefix)
host part (suffix)

7. Address Structure address bit mask notation
if a bit in mask is 1 -> equivalent bit in address:network bit
if a bit in mask 0, bit belongs : host part
, network mask ,
24 bits ON and 8 bits OFF
notation
network with mask  write /27

8. Subnets allows decentralized management of host addressing
use host address bits as additional network address bits
defined by changing the bit mask of the IP address
difference is that a subnet mask is only used locally

9. Subnets - Example Network 192.168.32.0/24 subdivide into 16 subnets
bit mask: , contains 256 addresses
subdivide into 16 subnets
use the mask , /28
first 3 bytes contain original network address block
4th byte is divided between subnet address and address of the host on subnet
4 high-order bits of the 4th byte as the subnet part of the address (1111)
last 4 bits of the 4th byte—as the host portion of the address (xxxx)
240 <-> 1111xxxx

10. Subnets - Example

11. Natural Mask IP address space
divided into 5 fixed-length structures (address classes)
3 main address classes
class A, class B, class C

12. Natural Mask

13. Private Network Numbers
host is connected to a private network, its IP address only needs to be unique within that private network
network numbers that are reserved for private use
Network (10/8 prefix)
24-bit block of addresses.
Networks to (172.16/12 prefix)
20-bit block of addresses.
Networks to ( /16 prefix)
16-bit block of addresses

14. Private Network Numbers
Advantages
It's easy.
not have to apply for an official address or get anyone's approval.
It's friendly.
save address space for those who need to connect to the Internet.
It's free.
RFC 1918 addresses cost nothing—public addresses cost money.
Disadvantage
have to change your address in the future if you directly connect your full network to the Internet and wish to make all of the systems on the network accessible from the Internet

15. IPv6
provides an enormous 128-bit address to solve the address depletion problem
can uniquely identify 3.4 x 1038 devices

16. IPv6
first three bits of the address indicate address type

17. IPv6 currently defined special-use addresses include
Unspecified address
all 128 bits are 0.
used to explicitly indicate that an address has not been assigned.
For example, a client might use an unassigned address as source address before being assigned an address by a configuration server.
Loopback address
first 127 bits are set to zeros followed by one bit set to 1.
serves same purpose as the IPv4 loopback address.
IPv4-compatible IPv6 address format
96 bits of zeros followed by a 32-bit IPv4 address.
used to tunnel IPv6 packets over IPv4 networks.
IPv4-mapped IPv6 address format
80 bits of zeros, 16 bits of ones, and then a 32-bit IPv4 address.
represent an IPv4 address as an IPv6 address.

18. IPv6 Global Routing Prefix Subnet ID is a 16-bit field
synonymous with the network portion of an IPv4 address
assigned to the enterprise by the address registry
Subnet ID is a 16-bit field
to create subnets within the larger network
like subnets in IPv4
does not require taking bits away from the host-specific portion of the address
64-bit Interface Identifier
analogous to the host portion of an IPv4 address

19. IPv6 IPv6 addresses are written using a colon-hexadecimal syntax
16-bit values separated by colons.

20. IPv6

21. Internet Routing Architecture
original Internet structure, there was a hierarchy of gateways
core gateways processed the information and then exchanged it among themselves using the Gateway to Gateway Protocol (GGP )

22. Routing Table
all network devices, hosts as well as gateways, must make routing decisions
If the destination host is on the local network, the data is delivered to the destination host.
If the destination host is on a remote network, the data is forwarded to a local gateway.
Using
simply table look-ups

23. Routing Table

24. Routing Table
all processes that use the Transport Layer protocols to deliver data
Telnet
The Network Terminal Protocol provides remote login over the network.
FTP
The File Transfer Protocol is used for interactive file transfer.
SMTP
The Simple Mail Transfer Protocol delivers electronic mail.
HTTP
The Hypertext Transfer Protocol delivers web pages over the network.

25. Routing Table

26. Protocols, Ports, and Sockets Protocol Numbers
identifies protocol in the layer above IP to which the data should be passed
a single byte in the third word of the datagram header
Windows system,
protocol numbers are documented in protocol file

27. Protocols, Ports, and Sockets Protocol Numbers

28. Protocols, Ports, and Sockets Port Numbers
Application processes (network services) identified by port numbers,
16-bit values
Port
Port numbers below 1024 are reserved for well-known services
Ports numbered from 1024 to are "registered ports.“
Windows Server 2003 systems
port numbers are listed in services file in the %SystemRoot%\system32\drivers\etc directory

29. Protocols, Ports, and Sockets Port Numbers

30. Protocols, Ports, and Sockets Port Numbers

31. Protocols, Ports, and Sockets
dynamically allocated ports
are not preassigned
assigned to processes when needed
to support multiple users
Ex telnet
first user is given a random source port number and a destination port number of 23 (Telnet).
second user is given a different random source port number and the same destination port
 combination of an IP address and a port number is called a socket

32. Protocols, Ports, and Sockets

33. Protocols, Ports, and Sockets
Use the netstat command to see active sockets onr Windows Server 2003