CCNA Guide to Cisco Networking

1
CCNA Guide to Cisco Networking

• Chapter 3 TCP/IP And IP Addressing

2
Objectives

• Discuss the origins of TCP/IP
• Understand the different classes of IP addresses
• Configure and verify IP addresses
• Subdivide an IP network
• Identify and discuss the different layer
  functions of TCP/IP

3
Objectives (continued)

• Describe the functions performed by protocols in
  the TCP/IP protocol suite, including ICMP, UDP,
  TCP, ARP, and RARP
• Use ping and trace and describe their functions
• Understand advanced routing concepts such as
  CIDR, summarization, and VLSM

4
Origins Of TCP/IP

• United States Department of Defense (DoD)
• Advanced Research Projects Agency (ARPA)
• Create a WAN to survive an nuclear attack
• Advanced Research Projects Agency Network
  (ARPANET)
• University of California at Santa Barbara (UCSB)
• University of California at Los Angeles (UCLA)
• Stanford Research Institute
• University of Utah

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Overview Of The TCP/IP Protocol Suite

• Application Layer
• File Transfer Protocol (FTP)
• Trivial File Transfer Protocol (TFTP)
• Network File System (NFS)
• Simple Mail Transfer Protocol (SMTP)
• Telnet
• rlogin
• Simple Network Management Protocol (SNMP)
• Domain Name System (DNS)
• Hypertext Transfer Protocol (HTTP)

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Overview Of The TCP/IP Protocol Suite (continued)

• Transport Layer
• Ports
• Well Known Port numbers
• TCP three-way handshake
• Initial sequence numbers
• Expectational acknowledgement
• Reset packet (RST)
• TCP sliding windows
• Flow control with sliding windows, buffering,
  congestion avoidance

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Overview Of The TCP/IP Protocol Suite (continued)

• Internetwork Layer
• Internet Protocol (IP)
• IPv4 and IPv6
• Internet Control Message Protocol (ICMP)
• Echo request, echo reply, and TTL
• Address Resolution Protocol (ARP)
• ARP table, ARP request, ARP reply, and TTL
• Reverse Address Resolution Protocol (RARP)
• RARP server and RARP client

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Overview Of The TCP/IP Protocol Suite (continued)

• Network Interface Layer
• Combines OSI Physical and Data Link layers
• MAC addresses
• Network card drivers
• Specific physical interfaces

9
Ping Utility
10
Ping Utility (continued)
11
Ping Utility (continued)
12
The Trace Utility
13
IP Addressing

• MAC to IP address translation
• IP classes
• Internet Assigned Numbers Authority (IANA)
• American Registry of Internet Numbers (ARIN)
• Internet Corporation for Assigned Names and
  Numbers (ICANN)
• Class A
• Class B
• Class C
• Class D
• Class E
• Private IP ranges

14
IP Addressing (continued)
15
IP Addressing (continued)
16
IP Addressing (continued)
17
IP Addressing (continued)
18
IP Addressing (continued)
19
Subnet Addressing

• Default class subnet masks
• Class A subnet mask is 255.0.0.0
  11111111.00000000.00000000.00000000
• Class B subnet mask is 255.255.0.0
  11111111.11111111.00000000.00000000
• Class C subnet mask is 255.255.255.0
  11111111.11111111.11111111.00000000
• Boolean ANDing operation
• Subnet addresses
• Broadcast addresses

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Broadcast Types

• Flooded broadcasts
• 255.255.255.255
• Directed broadcast
• 129.30.255.255

21
Subdividing IP Classes
22
Subnet Masking
23
Subnet Masking (continued)
24
Subnet Masking (continued)
25
Learning To Subnet
26
Learning To Subnet (continued)

• Breakdown of 255.255.255.244 subnet mask
• 0 (binary 00000000) unusable
• 32 (binary 00100000)
• 64 (binary 01000000)
• 96 (binary 01100000)
• 128 (binary 10000000)
• 160 (binary 10100000)
• 192 (binary 11000000)
• 224 (binary 11100000) unusable

27
Learning To Subnet (continued)
28
Learning To Subnet (continued)
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Subnetting Formulas

• 2y 2 of usable subnets (where y is the
  number of bits borrowed)
• 2x 2 of usable hosts per subnet (where x is
  the number of bits remaining in the host field
  after borrowing)

30
Subnetting Formulas (continued)
31
Subnetting Formulas (continued)
32
CIDR

• Classless Inter-Domain Routing (CIDR)
• Developed to slow the exhaustion of IP Addresses
• Provide efficient use of IP addresses and address
  ranges
• Subnetting and supernetting

33
Summarization

• Also known as route aggregation
• Move subnet mask bits left of the default
  boundary
• Combine several default class networks

34
Variable Length Subnet Masks
35
Variable Length Subnet Masks (continued)
36
Variable Length Subnet Masks (continued)
37
IPv4 Versus IPv6

• Internet Protocol version 4 is the most widely
  used
• 32-bit structure
• 232 available addresses
• Internet Protocol version 6 is not common but
  used
• 128-bit structure
• 2128 available addresses

38
Understanding Packet Transmission

• Routers on the network
• Network to network
• Dynamic or static tables
• Transmitting packets to remote segments
• Routing packets

39
Understanding Packet Transmission (continued)
40
Understanding Packet Transmission (continued)
41
Understanding Packet Transmission (continued)
42
Understanding Packet Transmission (continued)
43
Working With Hexadecimal Numbers
44
Summary

• TCP/IP is more than just the Transmission Control
  Protocol/Internet Protocol it is an entire suite
  of protocols that provides data transportation,
  management, and diagnostic capabilities for
  networks that use it
• TCP/IP was started by the Defense Advanced
  Research Projects Agency (DARPA)
• That group was charged with developing a national
  communication system that could survive a nuclear
  war
• Later, its network, ARPANET, was turned over to
  the public, especially universities
• From there, the Internet grew into what it is
  today, a large worldwide commerce and
  communications network

45
Summary (continued)

• TCP/IP maps to a four-layer network model
  Application, Transport, Internetwork, and Network
  Interface
• The Application layer in the TCP/IP model covers
  the Application, Presentation, and Session layers
  of the OSI reference model
• TCP/IP Transport layer maps directly to the OSI
  Transport layer
• The Internetwork layer of the TCP/IP model maps
  directly to the Network layer of the OSI model
• Network Interface layer of the TCP/IP model is
  equivalent to the Data Link and Physical layers
  of the OSI model

46
Summary (continued)

• The TCP and UDP protocols reside at the Transport
  layer of the TCP/IP networking Model
• UDP is an unreliable and connectionless
  communications protocol that does not guarantee
  packet delivery
• TCP is a reliable and connection-oriented
  protocol that guarantees packet delivery
• TCP uses a three-way handshake to establish a
  communications link between two points before
  data transfer
• TCP also uses a sliding window to control the
  flow of packets and the number of acknowledgments
  between the two hosts

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Summary (continued)

• Both TCP and UDP use port numbers from 1 to
  65,535 to establish their communications between
  two points
• Ports with numbers 1023 and under are Well Known
  Port numbers, as defined in RFC 1700
• These ports describe common Internet services
  that hosts can use to contact public servers for
  specific types of services, such as Web, FTP, and
  telnet
• The Internet Protocol (IP) resides at the
  Internetwork layer, it provides the logical
  address that can be passed through a router
• The subnet mask allows networks to be divided
  into subnetworks

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Summary (continued)

• You can use the ping utility with IP and ICMP to
  diagnose and troubleshoot network connections
• Use the trace utility with IP to determine all
  the hops that a packet makes along its path to a
  remote TCP/IP host
• Address Resolution Protocol (ARP) and Reverse ARP
  (RARP) reside in the Internetwork layer
• These protocols allow the TCP/IP host to map the
  IP address to a MAC address

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Summary (continued)

• The MAC address is the final leg of communication
  between hosts
• Packets are transmitted via the MAC address to
  the destination host once the packets arrive at
  the destination network or subnetwork
• The Internet Corporation for Assigned Names and
  Numbers (ICANN) and the American Registry of
  Internet Numbers (ARIN) work together to
  subdivide and issue addresses for Internet
  clients
• Three classes of addresses (A, B, and C) are
  available to organizations
• Class A addresses are for governments worldwide

50
Summary (continued)

• Class B addresses are assigned to medium to large
  companies and universities
• Class C addresses are assigned to organizations
  and people who require an IP address but do not
  meet the criteria to have a Class A or B address
• Class D addresses are used for multicasting
  information
• Multicasting allows anyone with the correct setup
  to broadcast a simultaneous transmission to
  multiple computers
• Class E addresses are used for experimentation
  and research

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Summary (continued)

• The subnet mask divides the network portion of
  the IP address from the host portion of the
  address
• The network or subnetwork IP address must always
  have zeros for the host identifier portion
• IP addresses that identify TCP/IP hosts must be
  nonzero in the host portion
• When the host portion of an IP address is all
  binary ones, the address is a broadcast address

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Summary (continued)

• Routing tables can be created manually and
  dynamically
• Network administrators manually create static
  routing tables
• A manual table requires more administrative
  overhead but gives the administrator greater
  control over the routing process
• Dynamic updates are provided through routing
  protocols
• The routing protocols allow the routers to be
  updated automatically

53
Summary (continued)

• Advanced routing protocols such as RIP version 2,
  OSPF, and EIGRP support variable length subnet
  masking (VLSM)
• VLSM allows network administrators to better
  allocate their IP address space by using
  different subnet masks on their subnetworks
• Classful routing protocols such as RIP version 1
  and IGRP do not support VLSM
• They require the same subnet mask on every subnet

54
Summary (continued)

• IPv6 is the latest version of IP addressing
• Unlike the 32-bit IPv4 addresses that are in use
  today on most networks, IPv6 addresses are 128
  bits long and are expressed in hexadecimal
• It is expected that vendors and networkers will
  slowly convert to IPv6 in the next several years

55
Summary (continued)

• The hexadecimal numbering system is also known as
  base 16 because there are 16 available numerals
• The numerals include all of the numbers 09 as
  well as the letters AF
• For example, the letter A represents the decimal
  number 10 and the letter F represents the decimal
  number 15
• Hexadecimal numbers are found in MAC addresses
  and IPv6 addresses, and are often used in
  computer and networking applications