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CISCO NETWORKING ACADEMY PROGRAM (CNAP)
SEMESTER 1/ MODULE 9
TCP/IP Protocol Suite &
IP Addressing
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Overview
• It is useful to know both the TCP/IP and OSI networking models.
• Any device on the Internet that wants to communicate with other
Internet devices must have a unique identifier (IP address).
• Because routers use a layer three protocol (IP protocol) to find the best
route to that device.
• IPv4 is the current version of IP.
• Subnetting, Network Address Translation (NAT) and private addressing
are used to extend IP addressing without exhausting the supply.
• IPv6 improves on the current version providing a much larger address
space.
• There are several methods of assigning an IP address to a device.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
TCP/IP History
• Requirement for the network that could
survive any conditions.
• Requirement for a reliable data transmission
to any destination on the network under any
circumstance.
• The TCP/IP model has since become the
standard on which the Internet is based.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Application Layer
• The TCP/IP combines all
application related issues into
one layer and assures this data
is properly packaged before
passing it on to the next layer.
• TCP/IP specifies common
applications
• The application layer handles
high-level protocols, issues of
representation, encoding, and
dialog control.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Transport Layer
• The transport layer provides transport services from the source
host to the destination host.
Transport services
include TCP and UDP
• The transport layer constitutes a logical connection between
the endpoints of the network, the sending host and the
receiving host.
• Transport protocols segment and reassemble upper-layer
applications into the same data stream between endpoints.
• The transport layer data stream provides end-to-end transport
services.
• End-to-end control, provided by sliding windows and reliability
in sequencing numbers and acknowledgments
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Transport Layer
TCP and UDP
• Segmenting upper-layer application data
• Sending segments from one end device to another end device
TCP only
• Establishing end-to-end operations
• Flow control provided by sliding windows
• Reliability provided by sequence numbers and acknowledgments
The transport layer sends data
packets from the sending
source to the receiving
destination through the cloud
(Internet).
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Internet Layer
• The purpose of the Internet layer is to determine Best path and to switch
packet.
• The main protocol that functions at this layer is the Internet Protocol (IP).
IP performs the following operations:
• Defines a packet and an addressing scheme
• Transfers data between the Internet layer and
network access layers
• Routes packets to remote hosts
Protocols operate
at this layer
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Internet Protocol
• IP is sometimes referred to as an unreliable protocol.
• This does not mean that IP will not accurately deliver data across a
network.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Network Access Layer
• The network access layer is also called the host-to-network layer.
• It includes the LAN and WAN technology details, and all the details
contained in the OSI physical and data-link layers.
• Drivers for software applications, modem cards and other devices
operate at the network access layer.
• The network access layer defines the procedures
for interfacing with the network hardware and
accessing the transmission medium.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Compare OSI and TCP/IP
• The TCP/IP model gains credibility because of its protocols.
• The OSI model is used as a guide for understanding the communication
process.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
IP Addressing
For any two systems to communicate, they must be able to identify and
locate each other.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
IP and MAC Addresses
• Each computer in a TCP/IP network must be given a unique identifier, or
IP address.
• The Layer 3 address allows one computer to locate another computer
on a network.
• All computers also have a unique physical address, known as a MAC
address.
• MAC addresses are assigned by the manufacturer of the network
interface card.
• MAC addresses operate at Layer 2 of the OSI model.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
IP Address
IP address
is 32-bit
address
Dotted Decimal Format
Using dotted decimal allows number patterns to be more easily understood.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Decimal and Binary Conversion
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Routers and IP addresses
• A router forwards packets from the originating network to the destination
network using the IP protocol.
• The packets must include an identifier for both the source and
destination networks.
• Using the IP address of destination network, a router can deliver a
packet to the correct network.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
IP Version 4 Addressing
• When the packet arrives at a router connected to the destination
network, the router uses the IP address to locate the particular
computer connected to that network.
• Every IP address has two parts:
(1) network and (2) host
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
IP Version 4 Addressing
• IP address is called a hierarchical address, because it contains
different levels
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
TCP/IP
• IP addresses are divided into classes to define the large, medium, and
small networks.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
TCP/IP
• Class A addresses are assigned to larger networks.
• Class B addresses are used for medium-sized networks
• Class C address is used for small networks.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Reserved IP Addresses
• Network address – Used to identify the network itself.
• An IP address that has binary 0s in all host bit positions is reserved
for the network address.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Network Address
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
TCP/IP
• Broadcast address – Used for broadcasting packets to all the devices
on a network.
• Broadcast IP addresses end with binary 1s in the entire host part of
the address.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Broadcast Address
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Public and Private Addresses
• Internet Assigned Numbers Authority (IANA) carefully manages the
remaining supply of IP addresses to ensure that duplication of publicly
used addresses does not occur.
• Public IP addresses are unique. No two machines that connect to a
public network can have the same IP address because public IP
addresses are global and standardized.
• With the rapid growth of the Internet, public IP addresses were
beginning to run out. (Sol. CIDR, IPV6, and Private IP addresses)
• Private IP addresses are another solution to the problem of the
impending exhaustion of public IP addresses.
• Private IP addresses are used within the closed network
• Connecting a network using private addresses to the Internet requires
translation of the private addresses to public addresses (or NAT).
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Public and Private Addresses
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Introduction to Subnetting
• Subnetting is another method of
managing IP addresses.
• This method of dividing full
network address classes into
smaller pieces has prevented
complete IP address exhaustion.
• Subnetting a network means to use the subnet mask to divide the
network and break a large network up into smaller, more efficient and
manageable segments, or subnets.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
IP Version 4
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
IP v4 Vs. IP v6
• IPv6 uses 128 bits rather than the 32 bits currently used in IPv4.
• IPv6 uses hexadecimal numbers to represent the 128 bits.
• IPv6 provides 640 sextrillion addresses.
• IPv6 fields are 16 bits long.
• IPv6 is slowly being implemented in select networks.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Obtaining IP Address
• A network host needs to obtain a globally unique address in order to function on
the Internet.
• The physical or MAC address that a host has is only locally significant.
• It identifies the host within the local area network.
• The router does not use it to forward outside the LAN based on Layer 2 address.
• IP addresses are the most commonly used addresses for Internet
communications.
• IP address is a hierarchical
addressing scheme that allows
individual addresses to be
associated together and treated
as groups.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Obtaining IP Address
• Network administrators use two methods to assign IP addresses.
• Static and Dynamic
Hosts have physical address by having NIC. IP addresses have
been assigned to the host in static/dynamic way
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Obtaining IP Address
• In static assignment, the system administrator manually assigns and
tracks IP addresses for each computer, printer, or server on the intranet.
• Static assignment works best on small, infrequently changing networks.
• Servers should be assigned a static IP address so workstations and
other devices will always know how to access needed services.
• Other devices that should be assigned static IP addresses are network
printers, application servers, and routers.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Obtaining IP Addresses
• Reverse Address Resolution Protocol (RARP) associates a known
MAC addresses with an IP addresses.
• Bootstrap Protocol (BOOTP) only requires a single packet exchange
to obtain IP information.
• Dynamic Host Configuration Protocol (DHCP) allows a host to obtain
an IP address dynamically without the network administrator having to
set up an individual profile for each device.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
RARP
• Reverse Address Resolution Protocol (RARP) associates a known
MAC addresses with an IP addresses.
• A network device, such as a diskless workstation, might know its MAC
address but not its IP address.
• RARP allows the device to make a request to learn its IP address.
• Devices using RARP require that a RARP server be present on the
network to answer RARP requests.
• The source device must include both its MAC address and IP address in
order for the destination device to retrieve data
• Workstations running RARP have codes in ROM that direct them to start
the RARP process.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
ARP/RARP Message Structure
Operation code = 1 ARP request
= 2 ARP reply
= 3 RARP request
= 4 RARP reply
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
RARP Operation
Computer FE:ED:F9:23:44:EF needs to get its IP address for internet operation
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
RARP Operation
Encapsulated
to be a frame
by adding
frame header
RARP Message
Computer FE:ED:F9:23:44:EF generate a ARP request
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
RARP Operation
Workstation
MAC& IP
Operation code
is 3 =
RARP Request
Target station
MAC& IP
Computer FE:ED:F9:23:44:EF generate a ARP request
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
RARP Operation
Computer FE:ED:F9:23:44:EF transmits RARP request
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
RARP Operation
All computers pass the packet up to network layer. If IP numbers do not match, the
packet is discarded except for RARP server,
which detects the RARP request field
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
RARP Operation
Workstation
MAC&
allocated IP
Operation code
is 4 =
RARP Reply
Server MAC&
IP
Server creates RARP reply message for the requesting client
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
RARP Operation
All computers copy frame and examine it
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
RARP Operation
If MAC address do not match, the packet is discarded
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
RARP Operation
Computer FE:ED:F9:23:44:EF stores the IP address received in the RARP reply
for later use
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
BOOTP
• The bootstrap protocol (BOOTP) operates in a client-server
environment and only requires a single packet exchange to obtain IP
information.
• However, unlike RARP, BOOTP packets can include the IP address, as
well as the address of a router, the address of a server, and vendorspecific information.
• One problem with BOOTP is that it was not designed to provide dynamic
address assignment.
• A network administrator needs to create a configuration file that specifies
the parameters for each device.
• The administrator must add hosts and maintain the BOOTP database.
• There is still a one to one relationship between the number of IP
addresses and the number of hosts.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
BOOTP Message Structure
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
BOOTP Operation
Computer FE:ED:F9:23:44:EF needs to obtain its IP address for Internet and
Intranet operation
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
BOOTP Operation
BOOTP request
message
Computer FE:ED:F9:23:44:EF generates a BOOTP request encapsulated in a
packet head and a frame header at network and data link layer orderly
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
BOOTP Operation
Workstation
MAC
Computer FE:ED:F9:23:44:EF broadcasts a BOOTP request to every node, since
it doesn’t know the server
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
BOOTP Operation
All computers pass BOOTP message up to transport layer, detect the BOOTP
message, other hosts discard this message except the server
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
BOOTP Operation
TFTP server and
gateway add
Workstation
MAC and
allocated IP
Server prepares a BOOTP response from its database to send back to
receiving device
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
BOOTP Operation
Server sends the BOOTP reply frame back to the requesting device. All devices
copy a frame and examine it
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
BOOTP Operation
If destination MAC doesn’t match, the workstation discarded the frame
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
BOOTP Operation
The requesting station makes use of the allocated IP address and other
information
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
DHCP
• Dynamic host configuration protocol (DHCP) allows a host to obtain an
IP address dynamically without the network administrator having to set
up an individual profile for each device.
• All that is required when using DHCP is a defined range of IP addresses
on a DHCP server.
• The major advantage that DHCP has over BOOTP is that it allows users
to be mobile.
• This mobility allows the users to freely change network connections from
location to location.
• The DHCP server chooses an address and leases it to that host.
• The importance to this DHCP advancement is its ability to lease an IP
address to a device and then reclaim that IP address for another user
after the first user releases it.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
DHCP Message Structure
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
DHCP Operation
Laptop computer AA:EC:F9:23:44:19 needs to get an IP address for Internet and
intranet operation
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
DHCP Operation
Laptop MAC
Workstation AA:EC:F9:23:44:19 generates a DHCP request (DHCP DISCOVER)
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
DHCP Operation
The DHCP request (DHCP DISCOVER) is transmitted by the laptop computer
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
DHCP Operation
All computers pass DHCP request (DHCP DISCOVER) up to transport layer,
detect the DHCP message, other hosts discard this message except the server
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
DHCP Operation
Allocated IP
Gateway
1st server prepares a DHCP OFFER to send back to the requesting devices
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
DHCP Operation
The DHCP server sends the DHCP OFFER frame back to the requesting device.
All devices pick up the frame and examine it.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
DHCP Operation
Match the laptop
MAC address
If MAC address doesn’t match, the devices discarded the frame.
Only the requesting station processes the frame.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
DHCP Operation
2nd server sends the DHCP OFFER frame back to the requesting device. All
devices pick up the packet and examine it
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
DHCP Operation
If MAC address doesn’t match, the devices discarded the frame.
Since the laptop has already received a DHCP OFFER from another server, this
offer is discarded.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
DHCP Operation
The laptop computer now sends a DHCP REQUEST addressed to the specific
DHCP server that sent the accepted OFFER
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
DHCP Operation
All devices pick up a copy of the frame, compare the MAC destination to their own,
and if there is no match, discard the frame
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
DHCP Operation
The DHCP server creates a DHCP ACK
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
DHCP Operation
The DHCP server sends the DHCP ACK frame back to the requesting device. All
devices pick up the frame and examine it
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
DHCP Operation
If the MAC doesn’t match, the devices discard the frame
and process the DHCP message
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
DHCP Operation
The laptop computer now goes into the bound mode and starts to use the
assigned IP address and other data passed with the DHCP OFFER message
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
DHCP Operation Summary
DHCP DISCOVER
DHCP OFFER
DHCP REQUEST
DHCP ACK
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Problem with Address Resolution
• A datagram on a local-area network must contain both a destination
MAC address and a destination IP address.
• Communications within a LAN segment require two addresses.
• There needs to be a way to automatically map IP to MAC addresses.
• The TCP/IP suite has a protocol, called Address Resolution Protocol
(ARP), which can automatically obtain MAC addresses for local
transmission.
• Both the IP and MAC addresses are needed for both the destination
host and the intermediate routing device.
• TCP/IP has a variation on ARP called Proxy ARP that will provide the
MAC address of an intermediate device for transmission outside the
LAN to another network segment.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
Proxy ARP
MAC address of the router is needed to get the data out of the LAN and
on to the WAN system
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
ARP
• Data packet must contain both a destination MAC address and a
destination IP address.
• After devices determine the IP addresses of the destination devices,
they can add the destination MAC addresses to the data packets.
• Some devices will keep tables that contain MAC addresses and IP
addresses of other devices that are connected to the same LAN.
• These are called Address Resolution Protocol (ARP) tables.
• ARP tables are stored in RAM memory.
• When a network device wants to send data across the network, it uses
information provided by the ARP table.
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
ARP Table
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
ARP Process
CISCO NETWORKING ACADEMY PROGRAM
CCNA 1/ MODULE 9
TCP/IP Protocol Suite & IP Add
ARP
• There are two ways that devices can gather MAC addresses.
• One way is to monitor the traffic that occurs on the local network
segment.
• Another way to get an
address pair for data
transmission is to
broadcast an ARP
request.