Internet Security Lesson One, 13 April

April 13, 2009
Network:
A Network is 2 or more computers connected together to share data, resources (printers)
The benefits are reduced costs, to max. productivity, save time by communicating (protocols)
Internet:
A combination of many networks working together
Protocol:
Transmission control protocol, internet protocol, (TCP/IP) largest protocol in the world
Every operating system by default uses TCP/IP
The more popular an item is the more at risk it is for a hacker.
You can have a computer with a multi protocol.
Data flows to and from, from the network card
Protocol stack:
Where multiple protocols appear in order (1.TCP/IP 2.Gopher)
TCP/IP has a predictable response just by saying “hi” a hacker can tell there is a computer, what operating system etc.
Customer oriented means less security, and therefore more at risk, hackers get the reward
LAN: Local area network- anything less than 2km in size
CAN: Campus area network- designed for campuses
WAN: Wide Area Network, 2 or more LAN’s-Larger than 2km
MAN: Metropolitan area network- City’s
Intranet: internal internet- private use only
Extranet: External intranet- access through intranet externally
Type of network relationship:
2 styles of networks:
1st Peer to Peer network:
All workstations, no longer ask questions to be done, able to do them on own.
Still able to share info. Based on security levels…example Windows XP
Physically plugged into individual workstation
2nd Client server network:
Client servers have to ask permission, and server asks for codes
Requires NOS-Network operating system… example windows server, Linux
Host: is a Node on a TCI/IP network
NODE: Any device that communicates on a network is known as a Node (router etc.)
Backbone: Will be a high speed connection that connects all together
Segment: the Distance on the network…branch of a network..2 communicating devices linked together
Scalability: the ability for your network to grow
Transmission Media: the devices on the network (physical) example: Ethernet cable
Subnet mask: combined with the IP= net work ID and Host ID—very important to where packet goes
sdhanapala@rogers.com
sdhanapala@conestogac.on.ca