 What is network?  Types of network ◦ LAN – Local Area - Ethernet ◦ WAN – Wide Area - Internet ◦ MAN – Metro. Area - LAN<=50km ◦ Wireless - WiFi ◦ PAN – Personal Area – Bluetooth ◦ Mobile Networks - CDMA/GSM/3G/4G etc ◦ WSN - Sensor Networks ◦ RFID (Radio Frequency Identification) Image Source:

OverviewA typical Network  Repeater ◦ Signal boost ◦ Example: Hub  Bridge ◦ Connections same types of networks ◦ Example: Switch  Routers ◦ Connects different types of networks  Gateway Connects different types of protocols Picture Source:

ExplanationExample  Server Port Numbers  80 – HTTP  20/21 – FTP  25 – SMTP  53 – DNS  Client Port Numbers  Image Source:

Type of Cables for LANRJ 45 Cable  RJ = Registered Jack  RJ 11 – Telephone  RJ 45 – Ethernet ◦ Straight Through ◦ Crossover ◦ Rollover Picture Source:

CyberAtlas.com  History  ARPANET (Advanced Research Projects Agency Network) was the first packet switching network created by United States Department of Defense during cold war.  Internet was first brought online in 1969 connecting 4 computers between UCLA, Stanford Research Institute, UCSB, and the University of Utah  Tim Berners-Lee joined with others, proposed a new protocol in 1989 for information distribution which is now known as World Wide Web.  It took 38 years for radio to reach 50 million users, 13 years for TV, and only 5 years for the Internet.

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  cmd – tracert

LinkWhat is inside the net?  /videoplay?docid= &e i=JTW6Su_3PI- MqAKnouzyAQ&q=war riors+on+the+net&hl= en# /videoplay?docid= &e i=JTW6Su_3PI- MqAKnouzyAQ&q=war riors+on+the+net&hl= en#  m/watch?v=Ve7_4ot- Dzs m/watch?v=Ve7_4ot- Dzs Picture Source:

OverviewComplications Image Source:

 At its peak infection rate, about 1 in 12 s on the Internet were MyDoom Viruses  It is estimated that PC Viruses cost businesses approximately $55 Billion in damages in  FTC received 161,000 identity theft complaints last year, the FBI estimates the actual number of victims is probably closer to 500,000

 Virus – Inside the machine  Worm – Machine to machine  Spyware – Collect information from the computer  Adware – Ads popup  Trojan – Type of malware control by a hacker  Phishing – fool the recipient by asking personal information  Network intrusions  Many more

Biometric Firewall Cryptography Anti- Spyware Antivirus IDS Mgmt rules Security