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PowerPoint Presentation - Cabrillo College

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									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                     DNS Server =
          Gateway
          75.140.156.1




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




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




   Rick Graziani graziani@cabrillo.edu            4
Rick Graziani graziani@cabrillo.edu   5
Rick Graziani graziani@cabrillo.edu   6
Rick Graziani graziani@cabrillo.edu   7
                        ISP                                             IP Address =
                        Internet
                        Service                                         Sub Mask =
                        Provider
                                                                        Default Gateway =
  24.205.224.36
                                                                        DNS Server =




                                                                        IP Address =

          Default
          Gateway                                                       Sub Mask =
          75.140.156.1
                                                                        Default Gateway =


          Public IP                                                     DNS Server =
          Address
          75.140.157.97

                                      Router/Default Gateway            IP Address =

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

                        Service                                         Sub Mask =
                        Provider                                              255.255.255.0
                                                                        Default Gateway =
  24.205.224.36                                                               192.168.1.1
                                                                        DNS Server =
                                                                              24.205.224.36



                                                                        IP Address =
                                                                               192.168.1.101
          Default
          Gateway
                                                           DHCP         Sub Mask =
          75.140.156.1                                                        255.255.255.0
                                                                        Default Gateway =
                                                                              192.168.1.1
          Public IP                                                     DNS Server =
          Address                                                              24.205.224.36
          75.140.157.97

                                      Router/Default Gateway            IP Address =

                                      Default Gateway: 192.168.1.1            192.168.1.102
                                      DHCP Server:                      Sub Mask =
                                      Network = 192.168.1.0                   255.255.255.0
                                      Sub Mask = 255.255.255.0          Default Gateway =
                                      First host: 192.168.1.100
                                                                              192.168.1.1
                                                                        DNS Server =
                                      Network Address Translation              24.205.224.36
Rick Graziani graziani@cabrillo.edu   75.140.157.97  192.168.1.host          9
Rick Graziani graziani@cabrillo.edu   10
Rick Graziani graziani@cabrillo.edu   11
                                                                               IP Address =
                                                                                      192.168.1.100
                                         I need an IP address                  Sub Mask =
                                         www.bayfed.com                              255.255.255.0
                                                                              Default Gateway =
     24.205.224.36                                                                   192.168.1.1
                       www.bayfed.com is at                                    DNS Server =
                       65.64.172.199                                                 24.205.224.36


ISP
Internet
              Default
Service       Gateway
Provider      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
                                                                                     IP Address =
                                                                                            192.168.1.100

                                                                                     Sub Mask =
                                                                                           255.255.255.0
                                                                                    Default Gateway =
     24.205.224.36                                                                         192.168.1.1
                                                                                     DNS Server =
                                                                                           85.255.112.1


ISP
Internet
              Default
Service                                  I need an IP address
              Gateway
Provider      75.140.156.1               www.bayfed.com




                                             Public IP
  Bay Federal                                Address
  65.74.172.199                              75.140.157.97

                                                                Router/Default Gateway
                                              www.bayfed.com is at
                           85.255.112.1       85.255.112.99


   85.255.112.99
   Rick Graziani graziani@cabrillo.edu
Rick Graziani graziani@cabrillo.edu   14
1981 primitive Internet report on KRON

http://www.youtube.com/watch?v=5WCTn4FljUQ&feature=pl
   ayer_embedded




Rick Graziani graziani@cabrillo.edu                     15
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                                           16
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                                          17
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                                18
Wireless Access Point

•   In our example the wireless access point (AP) will include a
    Router.




Rick Graziani graziani@cabrillo.edu                            19
Putting it together




•   Exactly the same as connecting a router without an AP.

Rick Graziani graziani@cabrillo.edu                          20
 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                    21
 Configuring the AP and Router

Wireless Settings:
• Security: WPA2, WPA, WEP, or none




                                       WPA2




 Rick Graziani graziani@cabrillo.edu          22
SSID

•   The SSID is what will be displayed when people with
    wireless computers are looking for a wireless LAN.




Rick Graziani graziani@cabrillo.edu                       23
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   24
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                           25
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                                           26
Rick Graziani graziani@cabrillo.edu   www.britishlibrary.net   27
Inverse square law
                   10                     20            30           40           50                    100




             Point A                                                                   10 times the distance
                                               3 times the distance
                                               1/9 the power of Point A                1/100 the power of A

                      2 times the distance                                5 times the distance
                      ¼ the power of Point A                              1/25 the power of Point A

• 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.




    Rick Graziani graziani@cabrillo.edu                                                                    28
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                                         29
Rick Graziani graziani@cabrillo.edu   30
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                            31
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                              32
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                                       33
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                          34
Wireless Security

                                      CommView   DriftNet




Rick Graziani graziani@cabrillo.edu                         35
Wireless Security

• Your web browsing or email access should already be secured.
• Look for the lock




Rick Graziani graziani@cabrillo.edu                              36
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&featur
      e=related




Rick Graziani graziani@cabrillo.edu                     37
MAC Cloning




Rick Graziani graziani@cabrillo.edu   38
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                   39
Rick Graziani graziani@cabrillo.edu   40
Careers in Information Technology




Rick Graziani graziani@cabrillo.edu   41
Computer Support Specialist




•   Installing computer hardware
    and software.
•   Troubleshooting
•   Maintenance and upgrades
Rick Graziani graziani@cabrillo.edu   42
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                          43
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                          44
Keeping up on technology




• Wireless
• Security
Rick Graziani graziani@cabrillo.edu   45
Internet: Safe Surfing
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   47
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                                            48
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                                      49
From Gain Publishing:
www.gainpublishing.com/ about/




 Rick Graziani graziani@cabrillo.edu   50
•      For early advertising-supported websites, banner ads were sufficient revenue
       generators.
•      But in the wake of the dot com crash, prices paid for banner advertising
       clickthroughs decreased and many vendors began to investigate more
       effective advertising methods.
•      Pop-up ads by their nature are difficult to ignore or overlook, and are claimed
       to be more effective than static banner ads.
•      Pop-ups have a much higher click rate than web banner ads do.
        – What are Pop-ups? (Wikipedia.org)
    Rick Graziani graziani@cabrillo.edu                                                  51
What are Pop-ups? (Wikipedia.org)

                                                     Ultimate
                                                     irony!




•     Most users regard pop-ups as a nuisance.
•     In the early 2000s, all major web browsers except Internet
      Explorer allowed the user to block pop-ups almost
      completely.
• In 2004, Microsoft released Windows XP SP2, which
      added pop-up blocking to Internet Explorer.
• Many of the latest pop-ups are created using Flash and
      have extensive animation and trickery.
 Rick Graziani graziani@cabrillo.edu                               52
Rick Graziani graziani@cabrillo.edu   53
    Pop-up, looks real…
http://www.news3insider.com/finance/google-hiring-you.html




     Rick Graziani graziani@cabrillo.edu                     54
Block Pop-up Windows with Internet
Explorer




Rick Graziani graziani@cabrillo.edu   55
C/NET – Pop-ups mean more $$$




•   Publishers willingly allow pop-ups or pop-unders
    because they command higher prices, and they're
    in high demand by advertisers.




Rick Graziani graziani@cabrillo.edu                    56
“Java Trap” or
“Pop-up Hell”




• Pornographic websites are among the most common users of pop-up
    ads.
•   Some particularly vicious types of pop-up ads have been specifically
    designed to "hijack" a user's Internet session.
•   As each window is closed by the user it activates another window --
    sometimes indefinitely.
•   Usually the only way to stop this is to close the browser.
•   Mouse Trapping: Another variation of pop-up fills an entire screen
    with an ad or Web page, removing any menu bars or other on-screen
    icons by which the user can close the window.
Rick Graziani graziani@cabrillo.edu                                        57
    Spyware (Wikipedia.org)




• Spyware is computer software that gathers and reports information
     about a computer user without the user's knowledge or consent.
•    May perform many different functions, including:
      – Delivery of unrequested advertising (pop-up ads in particular),
      – Harvesting private information
      – Re-routing page requests to illegally claim commercial site referral
        fees
•    Spyware or Malware Can include:
      – keystroke loggers
      – denial-of-service (DoS) attack agents

    Rick Graziani graziani@cabrillo.edu                                        58
Fighting Spyware




• Spybot (www.safer-networking.org)
• PestPatrol (www.pestpatrol.com)
Rick Graziani graziani@cabrillo.edu   59
Cookies
• A cookie is information sent by a
    server to a browser and then sent
    back to the server each time it
    accesses that server.
•   Amongst other uses, cookies
    enable websites to be customized
    for individual users once
    browsing patterns have been
    established.
•   Cookies only store information
    that you provide.




Rick Graziani graziani@cabrillo.edu     60
First time you login
                                      HTTP Requests: GET
                                      (first time)

       HTTP      HTTP: Response
       Server    Set-cookie: ID
                 5551212
                                HTTP Requests (GET)        HTTP Client
 Web server can now             now include ID -
 track clients activities       5551212
 on the web site.




Rick Graziani graziani@cabrillo.edu                                      61
Each time you login…

                                       HTTP: Cookie 5551212 included


     HTTP
                                      HTTP data customized
     Server
                                      for Rick Graziani
                                                                       HTTP Client




Rick Graziani graziani@cabrillo.edu                                                  62
Cookies - Purpose




• Typically this is used to authenticate or identify a registered user of a
    web site as part of their first login process or initial site registration
    without requiring them to sign in again every time they access that site.
•   Other uses are maintaining a "shopping basket" of goods selected for
    purchase during a session at a site, site personalization (presenting
    different pages to different users), and tracking a particular user's
    access to a site.
Rick Graziani graziani@cabrillo.edu                                           63
Cookies - Permissions




• A browser may or may not allow the use of cookies.
• The user can usually choose a setting.
• Microsoft Internet Explorer
      – Tools > Internet Options > Privacy Tab
      – Use slider to set options, or use advanced options
Rick Graziani graziani@cabrillo.edu                          64
Virus Protection




• In computer security technology, a virus is a self-
    replicating program that spreads by inserting copies of
    itself into other executable code or documents
Rick Graziani graziani@cabrillo.edu                           65
http://techguylabs.com/




Rick Graziani graziani@cabrillo.edu   66
Be careful when opening attachments!




Rick Graziani graziani@cabrillo.edu    67
•    “According to folks working on the case who talked to us at the HTCIA
     HighTech Crime Investigation Association international training this fall, the
     major method used by the Chinese hackers was to identify Google workers
     through their Facebook pages, trace back through their home town /
     highschool information, get the yearbook, make fake email / facebook accounts
     in the names of others from the yearbook, and make friends with the Google
     workers on the net. Eventually they sent them malware in photos which gave
Rick the Chinese the entry into the Google work systems.”
     Graziani graziani@cabrillo.edu                                                 68
Computer Virus, Spyware

•   Computer Virus, Spyware
•   http://www.youtube.com/watch?v=uK5ija2gVbY

•   How Computer Viruses Work
•   http://www.youtube.com/watch?v=sxal31zIKdE&feature=rel
    ated




Rick Graziani graziani@cabrillo.edu                      69
May 4th,
2009




  Rick Graziani graziani@cabrillo.edu   70
Spam (Wikipedia)




•   Spamming is the act of sending unsolicited electronic
    messages in bulk.




Rick Graziani graziani@cabrillo.edu                         71
Anti-Spam




• Spammers obtain e-mail addresses by a number of means:
      – Web pages
      – guessing common names at known domains
      – "e-pending"
      – searching for e-mail addresses corresponding to specific persons
•   Many e-mail spammers go to great lengths to conceal the origin of their
    messages.
•   Spoofing e-mail addresses - spammer modifies the e-mail message
    so it looks like it is coming from another e-mail address.
•   Among the tricks used by spammers to try to circumvent the filters is to
    intentionally misspell common spam filter trigger words, ie. "viagra"
    might become "vaigra", or by inserting other symbols within the word,
    i.e. "v/i/a/g./r/a".
Rick Graziani graziani@cabrillo.edu                                        72
The Nigerian Email Spam Scam

• Email SPAM Scam
• The Nigerian Email Spam Scam
• http://www.youtube.com/watch?v=kYNi2gVpuig

•   ABC Report on Nigerian Scammers
•   http://www.youtube.com/watch?v=8PQANsFisvU&feat
    ure=related
•   http://www.youtube.com/watch?v=7PVK0R01tRw&feat
    ure=related
•   http://www.youtube.com/watch?v=puYEUs18MFI&featu
    re=related


Rick Graziani graziani@cabrillo.edu                73
Passwords

• Combine letters, numbers, and symbols.
• Use words and phrases that are easy for you to remember, but difficult
    for others to guess.
•   Avoid sequences or repeated characters. "12345678," "222222,"
    "abcdefg,"
•   Avoid using only look-alike substitutions of numbers or symbols.
     – 'i' with a '1'
     – 'a' with '@‘
     – ‘o’ with a 0’
     – as in "M1cr0$0ft" or "P@ssw0rd"
•   At least 8 characters; more than14 characters is even better
•   But these substitutions can be effective when combined with other
    measures:
     – 1$erf@h00k


Rick Graziani graziani@cabrillo.edu                                        74
Hoaxes, Scams, and Fraud

•   This hoax generated
    thousands of emails with
    the first day alone.




Rick Graziani graziani@cabrillo.edu   75
Google name or go to Snopes.com




Rick Graziani graziani@cabrillo.edu   76
Virus Hoax

•   While it is true that
    PowerPoint files are
    capable of containing
    computer viruses, there
    is no evidence that an
    infected file called "Life Is
    Beautiful" even exists, let
    alone is circulating on
    the Internet.




Rick Graziani graziani@cabrillo.edu   77
Swiffer Wetjet




Rick Graziani graziani@cabrillo.edu   78
Typical Email Scam
Subject: Account Confirmation {Account Expires in 4 days}
Date:    Mon, 15 Sep 2008 06:14:39 -0400
From:     Leboyd, Nichole <nleboyd@msm.edu>
Dear Staff/Student

This message is from the IT Service messaging center to all subscribers/webmail users. We are currently upgrading the
     webmail data base and e-mail centers due to an unusual activities identified in our email system. We are deleting all
     unused Webmail Accounts. You are required to verify and update your Webmail by confirming your Webmail identity.
     This will prevent your Webmail account from been closed during this exercise. In order to confirm your Webmail
     identity, you are to provide the following data;

Confirm Your WebMail Identity Below;

First Name:
Last Name:
Username/ID:
Password:
Date of Birth:

Warning: Any subscriber/webmail user that refuses to verify and subsequently update his/her Webmail within 4 days of
    receiving this warning will lose his/her Webmail Account permanently.

We thank you for your prompt attention to this matter. Please understand that this is a security measure intended to help
    protect your Webmail Account. We apologise for any inconvenience.

Regards,
Leboyd Nichole
Webmail Administrator.




 Rick Graziani graziani@cabrillo.edu                                                                                         79
Wells Fargo (Scam)




Rick Graziani graziani@cabrillo.edu   80
Fake Site




Rick Graziani graziani@cabrillo.edu   81
Fake and Real Sites




Rick Graziani graziani@cabrillo.edu   82
Wells Fargo – Reporting Fraud Emails




Rick Graziani graziani@cabrillo.edu    83
PayPal




Rick Graziani graziani@cabrillo.edu   84
USAA




Rick Graziani graziani@cabrillo.edu   85
Changing Who From




Rick Graziani graziani@cabrillo.edu   86
Create Fake Email




Rick Graziani graziani@cabrillo.edu   87
Creating Fake Link




Rick Graziani graziani@cabrillo.edu   88
Receiver




Rick Graziani graziani@cabrillo.edu   89
Looking at Options doesn’t help




Rick Graziani graziani@cabrillo.edu   90
Click on Link…




Rick Graziani graziani@cabrillo.edu   91
RickRoll’D




Rick Graziani graziani@cabrillo.edu   92
Killer Whale Lands On Kayak (?)

•   http://www.youtube.com/watch?v=H2KBpauoDNs
•   http://www.youtube.com/watch?v=NjwxAJYKFbE




Rick Graziani graziani@cabrillo.edu              93
Sites to check for hoaxes

•   http://urbanlegends.about.com/od/internet/a/current_netlor
    e.htm
•   http://www.snopes.com/
•   http://www.hoax-slayer.com/




Rick Graziani graziani@cabrillo.edu                              94
Internet: Safe Surfing

           CS 1
       Rick Graziani

								
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