Download The Languages, Methods & Dynamics of the Internet

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
Objectives:
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The Languages,
Methods & Dynamics
of the Internet
Define Terms
Examine Scenarios
Learn about Tools
Learn about Resources
Perform Activities
Internet * Objects
Processes * Applications
Rules * IP Address
Names * Languages
Protection * Resources
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Network of networks
Objects
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Hosts
Interface Devices
Processes
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What is the Internet?
Communication
Internal Network management
Applications
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Internet Programs
Internet * Objects
Processes * Applications
Rules * IP Address
Names * Languages
Protection * Resources
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Gateways
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A gateway is a network point that acts as an
entrance to another network
Routers
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Traffic Control
Servers
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Internet Objects
Email
File
Web
Workstations
Printers
Internet * Objects
Processes * Applications
Rules * IP Address
Names * Languages
Protection * Resources
Internet Processes
Examples:
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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
Internet * Objects
Processes * Applications
Rules * IP Address
Names * Languages
Protection * Resources
Internet Processes
Examples:
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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
Internet * Objects
Processes * Applications
Rules * IP Address
Names * Languages
Protection * Resources
Examples:
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E-mail client
Web Browsers
Telnet clients
FTP clients
Custom Applications
Internet Applications
Internet * Objects
Processes * Applications
Rules * IP Address
Names * Languages
Protection * Resources
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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
Internet * Objects
Processes * Applications
Rules * IP Address
Names * Languages
Protection * Resources
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There are lots of ways to fool the
Internet into thinking that an address
is unique
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Exceptions to the Rules
Spoofing
There are lots of ways to fool the
Internet into thinking that one protocol
is really another protocol
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SOCKS5
Internet * Objects
Processes * Applications
Rules * IP Address
Names * Languages
Protection * Resources
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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
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Type A = xxx.yyy.yyy.yyy
Type B = xxx.xxx.yyy.yyy
Type C = xxx.xxx.xxx.yyy
Type D = xxx.xxx.xxx.xxx
Internet * Objects
Processes * Applications
Rules * IP Address
Names * Languages
Protection * Resources
Special IP addresses
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127.0.0.1
localhost
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xxx.xxx.xxx.0
domain
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xxx.xxx.xxx.255
broadcast address
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192.168.xxx.xxx
internal address
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10.1.xxx.xxx
internal address
Internet * Objects
Processes * Applications
Rules * IP Address
Names * Languages
Protection * Resources
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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
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Class A: 255.0.0.0
Class B: 255.255.0.0
Class C: 255.255.255.0
Internet * Objects
Processes * Applications
Rules * IP Address
Names * Languages
Protection * Resources
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Range from 0 to 65536
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Reserved: 1 through 1023
Registered: 1024 through 49151
Dynamic: 49152 through 65535
Some Reserved Ports
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FTP: Port 21
SMTP: Port 25
HTTP: Port 80
POP3: Port 110
Ports
Internet * Objects
Processes * Applications
Rules * IP Address
Names * Languages
Protection * Resources
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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
Internet * Objects
Processes * Applications
Rules * IP Address
Names * Languages
Protection * Resources
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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
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Range of IP addresses
Rules for lease
Internet * Objects
Processes * Applications
Rules * IP Address
Names * Languages
Protection * Resources
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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
Internet * Objects
Processes * Applications
Rules * IP Address
Names * Languages
Protection * Resources
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The Policemen of the Internet
Routers - Protocol Level
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A router is a device that determines the next
network point to which a packet should be
forwarded toward its destination
Firewalls - Network Level
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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
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A proxy server acts as an intermediary between a
workstation user and the Internet to ensure
security, administrative control, and caching
service
Exercise
Try some Internet commands
• IPCONFIG (Windows NT, 2000,
XP)
• PING
• TRACERT
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?
Exercise
Set up a Class C Network (cont’d)
• What are the addresses of the DNS
servers?
• DHCP Server
• Firewall
• Proxy Server
Internet * Objects
Processes * Applications
Rules * IP Address
Names * Languages
Protection * Resources
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Routers
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http://www.cisco.com
Network Calculator
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Resources
http://www.telusplanet.net/public/sparkm
an/netcalc.htm
Definition of Terms
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http://whatis.techtarget.com