Transcript CCNA 1 Module 9 TCP/IP Protocol Suite and IP Addressing

CCNA 1 Chapter 7
TCP/IP Protocol Suite and IP
Addressing
By
Your Name
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Objectives
• Introduction to TCP/IP
• Internet addresses
• Obtaining an IP address
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History and Future of TCP/IP
• The U.S. Department of
Defense (DoD) created
the TCP/IP reference
model because it wanted
a network that could
survive any conditions.
• Some of the layers in the
TCP/IP model have the
same name as layers in
the OSI model.
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Application Layer
• Handles high-level protocols, issues of
representation, encoding, and dialog control.
• The TCP/IP protocol suite combines all
application related issues into one layer and
ensures this data is properly packaged before
passing it on to the next layer.
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Application Layer Examples
• Telnet – Provides the capability to remotely
access another computer
• File Transfer Protocol – Download or upload files
• Hypertext Transfer Protocol – Works with the
World Wide Web
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Transport Layer
Five basic services:
• Segmenting upper-layer application data
• Establishing end-to-end operations
• Sending segments from one end host to another
end host
• Ensuring data reliability
• Providing flow control
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Layer 4 Protocols
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Internet Layer
• The purpose of the Internet layer is to send
packets from a network node and have them
arrive at the destination node independent of the
path taken.
• Internet layer protocols:
–
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Internet Protocol (IP)
Internet Control Message Protocol (ICMP)
Address Resolution Protocol (ARP)
Reverse Address Resolution Protocol (RARP)
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Network Access Layer
• The network access layer
is concerned with all of
the issues that an IP
packet requires to
actually make a physical
link to the network media.
• It includes the LAN and
WAN technology details,
and all the details
contained in the OSI
physical and data link
layers.
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Comparing the OSI Model and TCP/IP
Model
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Similarities of the OSI and TCP/IP
models
• Both have layers.
• Both have application layers, though they
include very different services.
• Both have comparable transport and network
layers.
• Packet-switched, not circuit-switched,
technology is assumed.
• Networking professionals need to know both
models.
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Differences of the OSI and TCP/IP
models
• TCP/IP combines the presentation and session
layer into its application layer.
• TCP/IP combines the OSI data link and physical
layers into one layer.
• TCP/IP appears simpler because it has fewer
layers.
• TCP/IP transport layer using UDP does not
always guarantee reliable delivery of packets as
the transport layer in the OSI model does.
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Internet Architecture
• Two computers, anywhere in the world, following
certain hardware, software, protocol
specifications, can communicate, reliably even
when not directly connected.
• LANs are no longer scalable beyond a certain
number of stations or geographic separation.
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Internet Addresses
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IP Address as a
32-Bit Binary Number
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Binary and Decimal Conversion
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IP Address Classes
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IP Address Classes
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IP Addresses as Decimal Numbers
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Hosts for Classes of
IP Addresses
Class A (24 bits for hosts) 224 - 2* = 16,777,214 maximum hosts
Class B (16 bits for hosts) 216 - 2* = 65,534 maximum hosts
Class C (8 bits for hosts) 28 - 2* = 254 maximum hosts
*
Subtracting the network and broadcast reserved address
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IP Addresses as Decimal Numbers
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Network IDs and Broadcast
Addresses
An IP address such as 176.10.0.0 that has all binary 0s in
the host bit positions is reserved for the network address.
An IP address such as 176.10.255.255 that has all binary 1s
in the host bit positions is reserved for the broadcast
address.
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Private Addresses
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Reserved Address Space
• Network ID
• Broadcast address
• Hosts for classes of IP addresses
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Basics of Subnetting
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Classical IP addressing
Subnetworks
Subnet mask
Boolean operations: AND, OR, and NOT
Performing the AND function
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Subnetworks
To create a subnet address, a network
administrator borrows bits from the original host
portion and designates them as the subnet field.
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Subnetworks
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Subnet Mask
• Determines which part of an IP address is the
network field and which part is the host field
• Follow these steps to determine the subnet mask:
– 1. Express the subnetwork IP address in binary form.
– 2. Replace the network and subnet portion of the
address with all 1s.
– 3. Replace the host portion of the address with all 0s.
– 4. Convert the binary expression back to dotted-decimal
notation.
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Subnet Mask
Subnet mask in decimal = 255.255.240.0
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Boolean Operations:
AND, OR, and NOT
• AND is like multiplication.
• OR is like addition.
• NOT changes 1 to 0, and 0 to 1.
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Performing the AND Function
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Range of Bits Needed to Create
Subnets
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Subnet Addresses
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Decimal Equivalents of 8-Bit
Patterns
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Creating a Subnet
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Determining subnet mask size
Computing subnet mask and IP address
Computing hosts per subnetwork
Boolean AND operation
IP configuration on a network diagram
Host and subnet schemes
Private addresses
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Determining Subnet Mask Size
Class B address with 8 bits borrowed for the subnet
130.5.2.144 (8 bits borrowed for subnetting) routes to subnet
130.5.2.0 rather than just to network 130.5.0.0.
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Determining Subnet Mask Size
Class C address 197.15.22.131 with a subnet
mask of 255.255.255.224 (3 bits borrowed)
11000101 00001111 00010110 100
Network Field
SN
00011
Host
Field
The address 197.15.22.131 would be on the
subnet 197.15.22.128.
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Subnetting Example
with AND Operation
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IP Configuration on a Network
Diagram
The router connects subnetworks and networks.
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Host Subnet Schemes
The number of lost IP addresses with a Class C network
depends on the number of bits borrowed for subnetting.
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IPv4 versus IPv6
• IP version 6 (IPv6) has been defined and
developed.
• IPv6 uses 128 bits rather than the 32 bits
currently used in IPv4.
• IPv6 uses hexadecimal numbers to represent
the 128 bits.
IPv4
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Obtaining an IP Address
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Obtaining an IP Address
• Static addressing
– Each individual device must be configured with an IP
address.
• Dynamic addressing
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Reverse Address Resolution Protocol (RARP)
Bootstrap Protocol (BOOTP)
Dynamic Host Configuration Protocol (DHCP)
DHCP initialization sequence
Function of the Address Resolution Protocol
ARP operation within a subnet
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Static Assignment of IP Addresses
• Each individual device must be configured
with an IP address.
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Reverse Address Resolution
Protocol (RARP)
The source initiates
a RARP request,
which helps it
detect its own IP
address.
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BOOTP IP
• The Bootstrap Protocol (BOOTP) operates in a
client/server environment and only requires a
single packet exchange to obtain IP information.
• BOOTP packets can include the IP address, as
well as the address of a router, the address of a
server, and vendor-specific information.
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Dynamic Host Configuration
Protocol
• Allows a host to obtain an IP address using a
defined range of IP addresses on a DHCP
server.
• As hosts come online, contact the DHCP server,
and request an address.
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DHCP Initialization Sequence
Client collects
DHCP offer
responses from
the server.
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ARP
t
ARP enables a computer
to find the MAC address
of the computer that is
associated with an IP
address.
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ARP Operation Within a Subnet
All devices on the network
receive the packet and pass to
network layer; only one device
responds with an ARP reply.
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ARP Process
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Advanced ARP Concepts
• Default gateway
• Proxy ARP
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Default Gateway
A default gateway is the IP
address of the interface on the
router that connects to the
network segment on which the
source host is located.
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How ARP Sends Data to Remote
Networks
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Proxy ARP
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