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The Languages, Methods Dynamics of the
Internet Bill Lester - NinthBridge

• E-mail is not to be used to pass on information
  or data. It should used only for company
  business!
• Memo from IBM Executive

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The Languages, Methods Dynamics of the Internet
Objectives

• Define Terms
• Examine Scenarios
• Learn about Tools
• Learn about Resources
• Perform Activities

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Internet ObjectsProcesses ApplicationsRules
IP AddressNames LanguagesProtection
Resources
What is the Internet?

• Network of networks
• Objects
• Hosts
• Interface Devices
• Processes
• Communication
• Internal Network management
• Applications
• Internet Programs

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Internet ObjectsProcesses ApplicationsRules
IP AddressNames LanguagesProtection
Resources
Internet Objects

• Gateways
• A gateway is a network point that acts as an
  entrance to another network
• Routers
• Traffic Control
• Servers
• Email
• File
• Web
• Workstations
• Printers

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Internet ObjectsProcesses ApplicationsRules
IP AddressNames LanguagesProtection
Resources
Internet Processes

• Examples
• Ping lets you verify that a particular IP
  address exists and can accept requests
• DNS resolution change host name into an IP
  address, using tables online
• Traceroute a utility that records the route
  through the Internet between your computer and a
  specified destination computer

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Internet ObjectsProcesses ApplicationsRules
IP AddressNames LanguagesProtection
Resources
Internet Processes

• Examples
• Whois a program that will tell you the owner of
  any second-level domain name
• Sendmail the most popular UNIX-based
  implementation of the Simple Mail Transfer
  Protocol (SMTP) for transmitting e-mail

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Internet ObjectsProcesses ApplicationsRules
IP AddressNames LanguagesProtection
Resources
Internet Applications

• Examples
• E-mail client
• Web Browsers
• Telnet clients
• FTP clients
• Custom Applications

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Internet ObjectsProcesses ApplicationsRules
IP AddressNames LanguagesProtection
Resources
Internet Rules

• Each Internet object must have a unique IP
  address
• Objects communicate with each other using one of
  the Internet processes
• Each application must have a unique Internet
  address and port
• Applications communicate with each other using an
  Internet protocol(s) and a port number

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Internet ObjectsProcesses ApplicationsRules
IP AddressNames LanguagesProtection
Resources
Exceptions to the Rules

• There are lots of ways to fool the Internet into
  thinking that an address is unique
• Spoofing
• There are lots of ways to fool the Internet into
  thinking that one protocol is really another
  protocol
• SOCKS5

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Internet ObjectsProcesses ApplicationsRules
IP AddressNames LanguagesProtection
Resources
What is an IP address?

• 32 bit number consisting of 4 octets
• The value in each octet ranges from 0 to 255
  decimal, or 00000000 - 11111111 binary
• Format xxx.xxx.xxx.xxx
• Type A, B, C, D
• Type A xxx.yyy.yyy.yyy
• Type B xxx.xxx.yyy.yyy
• Type C xxx.xxx.xxx.yyy
• Type D xxx.xxx.xxx.xxx

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Internet ObjectsProcesses ApplicationsRules
IP AddressNames LanguagesProtection
Resources
Special IP addresses

• 127.0.0.1 localhost
• xxx.xxx.xxx.0 domain
• xxx.xxx.xxx.255 broadcast address
• 192.168.xxx.xxx internal address
• 10.1.xxx.xxx internal address

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Internet ObjectsProcesses ApplicationsRules
IP AddressNames LanguagesProtection
Resources
Subnet Masks

• Method for sub-dividing IP address groups
• a 32-bit combination used to describe which
  portion of an address refers to the subnet and
  which part refers to the host
• Uses a hexadecimal mask
• Class A 255.0.0.0
• Class B 255.255.0.0
• Class C 255.255.255.0

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Internet ObjectsProcesses ApplicationsRules
IP AddressNames LanguagesProtection
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Ports

• Range from 0 to 65536
• Reserved 1 through 1023
• Registered 1024 through 49151
• Dynamic 49152 through 65535
• Some Reserved Ports
• FTP Port 21
• SMTP Port 25
• HTTP Port 80
• POP3 Port 110

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Internet ObjectsProcesses ApplicationsRules
IP AddressNames LanguagesProtection
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Unique Names

• DNS - The domain name system is the way that
  Internet domain names are located and translated
  into Internet Protocol addresses. A domain name
  is a meaningful and easy-to-remember "handle" for
  an Internet address.
• DNS Servers
• DNS Resolution
• Internal/External DNS Servers

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Internet ObjectsProcesses ApplicationsRules
IP AddressNames LanguagesProtection
Resources
Unique Names

• DHCP - Dynamic Host Configuration Protocol is a
  communications protocol that lets network
  administrators manage centrally and automate the
  assignment of Internet Protocol (IP) addresses in
  an organization's network.
• DHCP Server
• Range of IP addresses
• Rules for lease

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Internet ObjectsProcesses ApplicationsRules
IP AddressNames LanguagesProtection
Resources
Internet Languages (Protocols)

• TCP/IP - Application Processing
• SNMP - Network Management
• FTP - File Transfer
• HTTP - Web Browsing
• UDP - Random Processing
• IRC - Chat
• SMTP - Sending E-mail
• POP3 - Receiving E-mail
• NNTP - News Groups
• SLIP Serial Line Protocol
• PPP Point-to-Point Protocol

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Internet ObjectsProcesses ApplicationsRules
IP AddressNames LanguagesProtection
Resources
The Policemen of the Internet

• Routers - Protocol Level
• A router is a device that determines the next
  network point to which a packet should be
  forwarded toward its destination
• Firewalls - Network Level
• A firewall is a set of related programs, located
  at a network gateway server, that protects the
  resources of a private network from users from
  other networks
• Proxy Servers - Application Level
• A proxy server acts as an intermediary between a
  workstation user and the Internet to ensure
  security, administrative control, and caching
  service

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Exercise

• Try some Internet commands
• IPCONFIG (Windows NT, 2000, XP)
• PING
• TRACERT

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Exercise

• Set up a Class C Network
• Where do you get your Class C addresses?
• What is the domain address?
• What is the subnet mask?
• What is the broadcast address
• What is the address of the router/gateway?

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Exercise

• Set up a Class C Network (contd)
• What are the addresses of the DNS servers?
• DHCP Server
• Firewall
• Proxy Server

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Internet ObjectsProcesses ApplicationsRules
IP AddressNames LanguagesProtection
Resources
Resources

• Routers
• http//www.cisco.com
• Network Calculator
• http//www.telusplanet.net/public/sparkman/netcalc
  .htm
• Definition of Terms
• http//whatis.techtarget.com