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Technology in ActionTechnology in Action
Chapter 7
Networking and Security:Connecting Computers and Keeping Them Safe from
Hackers and Viruses
Chapter Seven ObjectivesChapter Seven Objectives• Networks
– Client/Server– Main components– Common types
• Hackers and harm
• Firewall
• Viruses
• Protection
Networking FundamentalsNetworking Fundamentals
• Definition
• Benefits
• Internet share
Network ArchitecturesNetwork Architectures
• Nodes
• Peer-to-peer
• Client/Server
Networks and DistanceNetworks and Distance
• LAN
• WAN
Data Transmission MediaData Transmission Media
• Twisted pair
• Coaxial
• Fiber optic
Data Navigation DevicesData Navigation Devices
• Packets
• Routers
• Hubs
Networking SoftwareNetworking SoftwareFor peer-to-peer
For client/server
Peer-to-Peer Network TypesPeer-to-Peer Network Types
• Power line
• Phone line
• Ethernet
• Wireless
Power Line NetworksPower Line Networks
• Uses house wiring– Max at 14 Mbps
• Power line network adapter– USB or Ethernet
• Plug and play– Software
• Routers and hubs • Uses phone lines
and jacks– Sharing with
phones– Max at 10 Mbps
• HPNA adapter or USB
• Routers and hubs
Ethernet Networks Ethernet Networks
• Most efficient– Usual speed at 100 Mbps
• Use unshielded twisted pair cable (UTP)
• Use routers and hubs
• Use NICS (network interface cards)
Ethernet CablingEthernet Cabling
• Installation, distance
• UTP categories
Cable CategoryMaximum Data Transfer Rate
Category 5 (CAT 5) 100 Mbps
Category 5E (CAT 5E) 200 Mbps
Category 6 (CAT 6) 1000 Mbps (1 Gbps)
Fig 7.11
Ethernet ArchitectureEthernet Architecture
• Hubs
• Routers– DSL/cable routers
• Internet
Wireless NetworksWireless Networks
• Radio waves, not cabling
• Wi-Fi – Several IEEE standards
• Wireless network adapter
• Transceiver
Wireless ConsiderationsWireless Considerations
• Range, signal degradation
• Node positions– Wireless access point
• Internet connection– Wireless DSL/cable routers
Peer-to-Peer QuestionsPeer-to-Peer Questions
• Existing wiring?
• Wireless also?
• How fast?
• Budget?
Comparing Home Networks Comparing Home Networks
Factors: Power Line
Phone Line
Ethernet
Wireless
Maximum data transfer rate (throughput)
14 Mbps
10 Mbps
100 to 1000 Mbps
11 to 54 Mbps
Approximate cost to network two computers (adapters and wiring only)
$160 $120 $135 $225
Additional cost for adding Internet connection sharing
$80 $120 $0 $40
Approximate cost to add a computer to network
$80 $60 $40 $60
Configuring Home Network Configuring Home Network SoftwareSoftware
• With XP
• With OS mix
• Without XP
Computer SafetyComputer Safety
• Cybercrime
• Cybercriminals
Computer Threats: Hackers Computer Threats: Hackers
• White hat
• Black hat
• Script kiddies
Why Hack?Credit cards
Packet sniffer
Identity theft
Safety TipsSafety Tips
• Hide passwords, pins
• Personal info
• Passwords:– Numbers and letters
– Obscure letter combinations
• FTC Identity Theft
Hacker ActivitiesHacker Activities• Trojan horses
– Far-reaching damage
– Back-door programs
• Denial of service
• Distributed DOS• Hacker access:
– Directly– Via logical ports
Firewall ProtectionFirewall Protection
Software– Easy, port protection
Hardware
Firewalls…Firewalls…
• Block ports
• Hide network address
• Use packet-filtering
• Use NAT
Computer-At-Risk TestingComputer-At-Risk Testing
• Free test fromGibson Research Corporation
Computer VirusesComputer Viruses
• Definition
• Kinds of damage
• Virus sources
Computer Viruses: TypesComputer Viruses: Types
• Grouped by behavior and method of transmission– Boot sector
– Logic bombs
– Worms
– Script and macro
– Trojan Horses
How Viruses Avoid DetectionHow Viruses Avoid Detection
• Polymorphic
• Multi-partite
• Stealth
Antivirus SoftwareAntivirus Software
• Norton
Antivirus SoftwareAntivirus Software
• Virus signatures
• Known viruses
• “Signature” updates
Other Security MeasuresOther Security Measures
• Update OS– System updates
– Security patches
Networking and Security Networking and Security Topic SummaryTopic Summary
• What is a network– Advantages
• Difference between a client/server network
and a peer-to-peer (P2P)
• Main network components
• Common home networks
• Power line networks
• Phone line networks
Networking and Security Networking and Security Topic SummaryTopic Summary
• Ethernet networks
• Wireless networks
• How hackers attack– Harm
• Firewall– How does it keep a computer safe
• Viruses
• Protection