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Networking Fundamentals - Part 2

Networking Fundamentals - Part 2. CS 1 Rick Graziani Cabrillo College. ISP Internet Service Provider. IP Address =. 24.205.224.36. Sub Mask =. Default Gateway =. Default Gateway 75.140.156.1. DNS Server =. ISP Internet Service Provider. DHCP. IP Address =. 24.205.224.36.

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Networking Fundamentals - Part 2

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  1. Networking Fundamentals - Part 2 CS 1 Rick Graziani Cabrillo College

  2. ISP Internet Service Provider IP Address = 24.205.224.36 Sub Mask = Default Gateway = Default Gateway 75.140.156.1 DNS Server = Rick Graziani graziani@cabrillo.edu

  3. ISP Internet Service Provider DHCP IP Address = 24.205.224.36 75.140.157.97(Public) Sub Mask = 255.255.255.252 Default Gateway = 75.140.156.1 Default Gateway 75.140.156.1 DNS Server = 24.205.224.36 Rick Graziani graziani@cabrillo.edu

  4. DSL/Cable Modem Router Rick Graziani graziani@cabrillo.edu

  5. Rick Graziani graziani@cabrillo.edu

  6. Rick Graziani graziani@cabrillo.edu

  7. Rick Graziani graziani@cabrillo.edu

  8. ISP Internet Service Provider IP Address = Sub Mask = Default Gateway = 24.205.224.36 DNS Server = IP Address = Default Gateway 75.140.156.1 Sub Mask = Default Gateway = DNS Server = Public IP Address 75.140.157.97 Router/Default Gateway IP Address = Default Gateway: 192.168.1.1 DHCP Server: Network = 192.168.1.0 (Private) Sub Mask = 255.255.255.0 First host: 192.168.1.100 Sub Mask = Default Gateway = DNS Server = Network Address Translation 75.140.157.97  192.168.1.host Rick Graziani graziani@cabrillo.edu

  9. ISP Internet Service Provider IP Address = 192.168.1.100 Sub Mask = 255.255.255.0 Default Gateway = 192.168.1.1 24.205.224.36 DNS Server = 24.205.224.36 IP Address = 192.168.1.101 Default Gateway 75.140.156.1 DHCP Sub Mask = 255.255.255.0 Default Gateway = 192.168.1.1 DNS Server = Public IP Address 75.140.157.97 24.205.224.36 Router/Default Gateway IP Address = 192.168.1.102 Default Gateway: 192.168.1.1 DHCP Server: Network = 192.168.1.0 Sub Mask = 255.255.255.0 First host: 192.168.1.100 Sub Mask = 255.255.255.0 Default Gateway = 192.168.1.1 DNS Server = Network Address Translation 75.140.157.97  192.168.1.host 24.205.224.36 Rick Graziani graziani@cabrillo.edu

  10. Rick Graziani graziani@cabrillo.edu

  11. Rick Graziani graziani@cabrillo.edu

  12. IP Address = 192.168.1.100 I need an IP address www.bayfed.com Sub Mask = 255.255.255.0 Default Gateway = 192.168.1.1 24.205.224.36 DNS Server = www.bayfed.com is at 65.64.172.199 24.205.224.36 ISP Internet Service Provider Default Gateway 75.140.156.1 Public IP Address 75.140.157.97 Bay Federal 65.74.172.199 Router/Default Gateway Rick Graziani graziani@cabrillo.edu

  13. IP Address = 192.168.1.100 Sub Mask = 255.255.255.0 Default Gateway = 192.168.1.1 24.205.224.36 DNS Server = 85.255.112.1 ISP Internet Service Provider Default Gateway 75.140.156.1 I need an IP address www.bayfed.com Public IP Address 75.140.157.97 Bay Federal 65.74.172.199 Router/Default Gateway www.bayfed.com is at 85.255.112.99 85.255.112.1 85.255.112.99 Rick Graziani graziani@cabrillo.edu

  14. Rick Graziani graziani@cabrillo.edu

  15. 1981 primitive Internet report on KRON http://www.youtube.com/watch?v=5WCTn4FljUQ&feature=player_embedded Rick Graziani graziani@cabrillo.edu

  16. Circuit Switched • Circuit Switching:A form of data communication which establishes a single connection or circuit between source and destination to carry the data stream. • Like a conventional telephone system. • When a subscriber makes a telephone call the dialed number is used to set switches in the exchanges along the route of the call so that there is a continuous circuit from the originating caller to that of the called party. Rick Graziani graziani@cabrillo.edu

  17. Packet Switching • Packet Switching: A form of data communications which breaks a data stream into small sections, sends them separately by the best available channels and reassembles the original data stream at its destination. • An alternative is to allocate the capacity to the traffic only when it is needed, and share the available capacity between many users. Rick Graziani graziani@cabrillo.edu

  18. Wireless Access Point • A wireless access point is a device that connects wireless devices (laptops, etc.) to a wired network, usually an Ethernet LAN. Rick Graziani graziani@cabrillo.edu

  19. Wireless Access Point • In our example the wireless access point (AP) will include a Router. Rick Graziani graziani@cabrillo.edu

  20. Putting it together • Exactly the same as connecting a router without an AP. Rick Graziani graziani@cabrillo.edu

  21. Configuring the AP and Router Wireless Settings: • SSID (Service Set Identifier) – Name of your network • Security: WPA2, WPA, WEP, or none SSID Rick Graziani graziani@cabrillo.edu

  22. Configuring the AP and Router Wireless Settings: • Security: WPA2, WPA, WEP, or none WPA2 Rick Graziani graziani@cabrillo.edu

  23. SSID • The SSID is what will be displayed when people with wireless computers are looking for a wireless LAN. Rick Graziani graziani@cabrillo.edu

  24. Linksys WRT54G Router Information • IP Address from ISP • Connects to your DSL/Cable Modem • NAT (Network Address Translation) Local Network • Ethernet Switch • Connect “wired” computers • DHCP Server (optional) Wireless • SSID: MyHomeNetwork • DHCP Server: (optional) • Channel: 11 • Encryption Function: WPA Rick Graziani graziani@cabrillo.edu

  25. You choose… • There are many resources to discuss the possible health risks or wireless LANs. • As a networking and WLAN user and instructor I have my own thoughts which I will share. • If you are concerned, then research the information and come to your own conclusions. • The following information is from my own research and experience. Rick Graziani graziani@cabrillo.edu

  26. Wireless Frequency • Wireless APs operate at: • 2.4 GHz • 5 GHz • 2 GHZ! That’s the same as my microwave oven, isn’t that dangerous? • Answer: No. • Electromagnetic waves happen naturally. • Light is an electromagnetic wave • It is not the frequency, but the wattage, the power. • Any electromagnetic wave can be dangerous with too much power. • A 25 watt light bulb is safe, but it wouldn’t be safe at 250,000 watts • Wireless access points generate signals at 1/10th of a watt. • Like all electromagnetic waves, the signal does not fade in a linear manner, but inversely as the square of the distance. Rick Graziani graziani@cabrillo.edu

  27. www.britishlibrary.net Rick Graziani graziani@cabrillo.edu

  28. Inverse square law 10 20 30 40 50 100 • Double the distance of the wireless link, we receive only ¼ of the original power. • Triple the distance of the wireless link, we receive only 1/9 the original power. • Move 5 times the distance, signal decreases by 1/25. Point A 10 times the distance 1/100 the power of A 3 times the distance 1/9 the power of Point A 2 times the distance ¼ the power of Point A 5 times the distance 1/25 the power of Point A Rick Graziani graziani@cabrillo.edu

  29. Putting it in some perspective • Measurements from an antenna transmitting 100mW at 1 inch • Remember a milliwatt is 1/1,000th of a Watt • Microwave oven typically operates at 1,000 watts in a confined space. 1” 100 mW 1/10th watt 2” 25 mW 1/40th watt 4” 6.25 mW 1/166th watt 8” 1.56 mW 1/1000th watt 16” 0.39 mW 4/10,000th watt 32” 0.097 mW 1/10,000th watt 64” (5.3 ft) 0.024 mW 2/100,000th watt 128” (10.6 ft) 0.006 mW 6/1,000,000th watt 256” (21.3 ft) 0.0015 mW 15/10,000,000th watt • Light bulbs would also be dangerous the were 10,000 to 1,000,000,000,000 stronger. • A 250,000 watt up to a 250,000,000,000,000 watt light bulb would also be dangerous. Rick Graziani graziani@cabrillo.edu

  30. Rick Graziani graziani@cabrillo.edu

  31. Wireless N • Wireless N provides better speeds (bandwidth) and better range by utilizing multiple antennas. • Backwards compatible with 802.11 b and g. Rick Graziani graziani@cabrillo.edu

  32. Wireless Security – Everyone can hear • Others can “hear” or capture your information. • Wireless signals are propagated, sent, similar to our voice sound waves. Rick Graziani graziani@cabrillo.edu

  33. Wireless Security – Everyone can hear • If we don’t want them to understand what they hear, we can encrypt or code the information. • As long a our wireless computer and access point are using the same encryption algorithm, such as WEP or WPA. Rick Graziani graziani@cabrillo.edu

  34. Wireless Security • Without any security, anyone can: • Use your wireless access point to access your network and the Internet. • Capture your information from your wireless computer. Rick Graziani graziani@cabrillo.edu

  35. Wireless Security CommView DriftNet Rick Graziani graziani@cabrillo.edu

  36. Wireless Security • Your web browsing or email access should already be secured. • Look for the lock Rick Graziani graziani@cabrillo.edu

  37. Wireless Security • Why you should protect your wireless network with WPA • http://www.youtube.com/watch?v=A88XB7_Jz7s • Wireless Hacking • http://www.youtube.com/watch?v=qP1BOZqrp5g&feature=related Rick Graziani graziani@cabrillo.edu

  38. MAC Cloning Rick Graziani graziani@cabrillo.edu

  39. Cell Phones do not cause explosions • http://www.youtube.com/watch?v=OQ0aTMMITp8 • http://www.youtube.com/watch?v=NRGrFLRs9xE&feature=related Rick Graziani graziani@cabrillo.edu

  40. Rick Graziani graziani@cabrillo.edu

  41. Careers in Information Technology Rick Graziani graziani@cabrillo.edu

  42. Computer Support Specialist • Installing computer hardware and software. • Troubleshooting • Maintenance and upgrades Rick Graziani graziani@cabrillo.edu

  43. Networking: System Administrator • Installing, configuring, and maintaining network servers • UNIX, LINUX, Microsoft • Web, DNS, DHCP, Mail Servers • Backup and recovery, user administration • Security Rick Graziani graziani@cabrillo.edu

  44. Networking: Network Technician/Analyst • Install, manage, troubleshoot network infrastructure: • Routers, Switches, Cables, Wireless Access Points • Issues: Security, Quality of Service, Video On Demand, Voice over IP Rick Graziani graziani@cabrillo.edu

  45. Keeping up on technology • Wireless • Security Rick Graziani graziani@cabrillo.edu

  46. Internet: Safe Surfing

  47. Safe Surfing • Adware • Pop-ups • Spyware • Blocking Pop-ups • Java Traps or Pop-Up Hell • Spyware • Blocking Spyware • Cookies • Virus Protection • Spam • Blocking Spam Rick Graziani graziani@cabrillo.edu

  48. Adware • Adware or advertising-supported software is any software application in which advertisements are displayed while the program is running. • Adware helps recover programming development costs, and helps to hold down the price of the application for the user (even making it free of charge)—and, of course, it can give programmers a profit, which helps to motivate them to write, maintain, and upgrade valuable software. Rick Graziani graziani@cabrillo.edu

  49. What are Pop-ups? (Wikipedia.org) • Pop-up ads are a form of online advertising on the Web where certain websites open a new web browser window to display advertisements. • Usually generated by JavaScript • A less intrusive variation on the pop-up window is the pop-under advertisement. • This opens a new browser window, but in the background, so as not to interrupt the user's page-view. Rick Graziani graziani@cabrillo.edu

  50. From Gain Publishing: www.gainpublishing.com/ about/ Rick Graziani graziani@cabrillo.edu

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