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What's a firewall?

From: Monday Productivity Pointers

Video: What's a firewall?

Hi there, Jess Stratton here, and welcome to Monday Productivity Pointers. This week on Monday Productivity, I thought In this video I am going to talk about what a Firewall is.

What's a firewall?

Hi there, Jess Stratton here, and welcome to Monday Productivity Pointers. This week on Monday Productivity, I thought I'd go back to basics a little bit. Because, knowing how the Internet works goes a long way in learning how to do your own troubleshooting. So this week I am going to talk about Firewalls, now if you have Internet access at home you most likely had to purchase a Firewall router or maybe you tried to do something on your browser or work and you got blocks because of their Firewall. In this video I am going to talk about what a Firewall is.

What it does. What is blocking? And I'm going to talk a little bit about how data travels through the Internet using ports. It monitors how traffic, that is data, goes over the Internet to finally get to you. So we have a lot to cover, so I"m going to get started. I've got some common ports open here on my screen. And I'm going to get to those in a second. But first thing we need to cover, to understand what this means, is how data travels through the Internet. Different types of data that open with different types of apps.

Such as a web browser versus an email program. Travel through different ports. So what's a port? Well I like to use radio stations traveling through airwaves as a perfect way to explain it. Radio waves travel through the air and your radio is a receiver. It picks up the airwaves on the other end. Now, each dial on your radio is set to a different frequency of what radio wave is traveling. So to get to the country music station, you might set your dial to 99.5. To get rock, move the dial to a station that's listening on a different frequency.

Say 103.7, if we can move this analogy to the computer. Instead of a frequency on an airway, different kinds of internet data travels through different port number. Your computer has a built in firewall, in addition to the firewall on your router. So think of the firewall as the radio portion of the analogy. The firewall is always listening for data traveling on various ports and from there it knows what app to send the right data to.

Sometimes internet data travels through a certain port number that your firewall won't allow. In that case the firewall won't send the data through, it just won't allow it to pass. So, here's some common internet ports. And remember, ports are how data travels through the internet. So, you may have seen port 110, or POP3 e-mail or port 25 which is how SMTP e-mail travels. There's also port 143 which is how IMAP, which is the third way of sending e-mail, travels through the internet.

Now, when you open a web browser and you're browsing websites, you're using a protocol named HTTP and that actually travels over port 80. And when you do secure browsing such as a shopping checkout screen, you may notice that your browser changes to the HTTPS protocol at the top of the screen. A padlock also appears at that time. That time your browsers switches to port number 443. You've also probably seen these ports in action without realizing it.

When you setup an email account, you specify the incoming server. Say mail.verizon.net. I'm going to open up this browser, where I took a procedure online. Or how to connect to the internet, you may have seen these instructions. For example, when you're hooking up a new email system, and they have their own instructions as to how to configure your email client. So these are ports in action, when you setup the email account, you have to specify the incoming server, say mail.verizon.net. And you have to specify that it's going to come in on port 25.

That's why port 25 is this well known standard port that's used to send email. For the last thing I want to cover when I talk about firewalls is what happens when something is blocked that you need to get through. Well, usually, firewalls are doing their job, and protect you from malicious software traveling through various ports on the internet. And you may have ports open on your computer, in which case that data can just get right through. So if you're at an office, and your administrator has blocked it, there's nothing you can do about it short of going in and talking to your administrator about it.

But when you're home, you have some more choices. I'm going to open up this window here. This is what a typical home network diagram looks like. This cloud over here is the internet. This is the unknown internet. Over here, this little brick wall, this is what your external IP address is. Now every network has an IP address. What you may not realize is you actually have two. You have an internal one that's only known to your local area network, and an external one, the IP address that's visible to the rest of the world.

Now the job of your firewall modem down here is to provide the rest of the world with that external address. But hide your internal address. So I can see here that there's one external address that's pointing to the internet. Now, my firewall modem has two. It has an external IP address of 64.156.76.34. But it also has this special internal IP address, which is 192.168.1.1. That may sound familiar to you.

It's also frequently something like 10.0.0.1. So the job of this modem is to be a firewall, and to block any traffic that's coming through to this external address. Evaluate the port number, and see where it's going. As you can see, on my internal network. I have things like an XBox console, and an iPhone. And maybe some family desktop computers and some laptops, and also a printer. All those things have to get their own IP addresses. Now, it's outside the scope of this lesson how to see what they are, but it's very easy to find out what the actual internal and external IP address of your devices.

So, what happens when traffic is blocked from this firewall and we really want it to get through? Well in this case, you need to look up in the manual of your firewall to know how to log into it. Because you can actually control those settings. So the last thing I want to show you is this tab I have over here. This is what happens when you login to your firewall router. You get a web interface in which you can do things like change the wireless name and the wireless password for everybody to use. But way over here on the left hand side of the screen, I'm more interested in something called Port Forwarding.

So when I come into this screen, I can see a service name that I want to add. Plus the starting point and the end point, and finally the computer name that it's going to. Now that's the internal IP address name. So don't worry if you don't understand this too much. The point is just to understand how data travels over the internet. And how you do have quite a bit of control to block it and allow and fine tune where you want that traffic to go.

Show transcript

This video is part of

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Monday Productivity Pointers

123 video lessons · 51712 viewers

Jess Stratton
Author

 
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  1. 2m 36s
    1. Getting alerts for Amazon price drops
      2m 36s
  2. 10h 37m
    1. Welcome to the series
      1m 13s
    2. Running a group meeting with coworkers
      7m 19s
    3. Recording and marketing chat on air
      8m 30s
    4. Creating a quick presentation
      5m 37s
    5. Presenting from an iPad or computer
      3m 36s
    6. Migrating your accounts to Mint.com
      9m 55s
    7. Setting budgets and goals
      7m 4s
    8. Collaborating on team documents
      5m 53s
    9. Creating an online photo gallery
      4m 58s
    10. Kickstarter: Setting up your project
      10m 41s
    11. Driving traffic to your project
      5m 48s
    12. Conducting a voice call with a virtual team
      6m 40s
    13. Adding video and chat notifications
      4m 7s
    14. Accepting a payment with Square
      4m 35s
    15. Using the Square Wallet
      2m 32s
    16. Setting up shop on Etsy
      6m 31s
    17. Tracking your Etsy sales with Shop Stats
      4m 9s
    18. Raising your Klout score
      7m 3s
    19. Earning Klout perks
      4m 55s
    20. Skydrive: Collaborating on team documents
      4m 56s
    21. Skydrive: Accessing files on the go
      2m 57s
    22. Setting up Google alerts to track your data
      5m 5s
    23. Removing a page from the Google search index
      4m 42s
    24. Browsing privately in public
      4m 38s
    25. Cleaning up your session before logging out
      5m 8s
    26. Troubleshooting a remote computer with TeamViewer
      3m 42s
    27. Taking screenshots from a PC
      4m 12s
    28. Taking screenshots from a Mac
      3m 36s
    29. Setting up Find My iPhone
      3m 36s
    30. Using iCloud to find an iPhone
      3m 49s
    31. Sampling color from the screen
      5m 27s
    32. Using ColourLovers.com for inspiration
      3m 22s
    33. Get an audio clip onto YouTube using iPhoto
      5m 49s
    34. Creating playlists and customizing your YouTube channel
      5m 41s
    35. Record your screen using QuickTime
      3m 14s
    36. Record your screen using CamStudio
      2m 34s
    37. Using Tempo Smart Calendar when you are going to be late
      3m 9s
    38. Using Twist to let your customers know where you are
      3m 38s
    39. Using Wunderlist to track multiple projects
      9m 0s
    40. Use the Wunderlist browser extension to create tasks on the web
      5m 46s
    41. Using Smart Mailboxes with Mac Mail
      6m 52s
    42. Customizing the Mac Mail View
      7m 13s
    43. What's a firewall?
      7m 36s
    44. What is the Cloud?
      4m 42s
    45. Creating your own recipe with IFTTT
      7m 19s
    46. Browsing existing recipes with IFTTT
      5m 7s
    47. Installing the Feedly browser extension
      6m 34s
    48. Customizing Feedly
      6m 53s
    49. Understanding the basics of Twitter
      9m 9s
    50. Using Tweetdeck to handle multiple accounts
      9m 14s
    51. Working with URL Shorteners
      5m 45s
    52. Using bit.ly
      8m 31s
    53. Creating Quick Parts to re-use text
      6m 19s
    54. Moving your Autotext to a new computer
      6m 7s
    55. Shutting off access to social networks
      6m 18s
    56. Hiding taskbars
      2m 36s
    57. Exploring the iOS 7 Update
      10m 7s
    58. Running a productive online meeting
      3m 44s
    59. Getting meeting minutes faster
      6m 47s
    60. TextExpander for Mac
      7m 6s
    61. Breevy for Windows
      3m 44s
    62. Using Smart Folders on a Mac
      5m 52s
    63. Using Windows Libraries
      4m 25s
    64. Finding large attachments in your email apps
      5m 13s
    65. Use Ninite to install all your PC apps at once
      3m 30s
    66. Use Get Mac Apps to install your Mac apps at once
      2m 56s
    67. Creating a disposable email address with Guerrilla mail
      4m 7s
    68. Creating an email address that lasts only 10 minutes
      3m 16s
    69. Finding and adding local vendors to enhance your iOS reminders
      3m 45s
    70. Adding geofencing to Find My Friends
      3m 20s
    71. Turning a Word document contract into a PDF
      4m 1s
    72. Turning a PowerPoint presentation into a PDF
      4m 10s
    73. Resetting browser site passwords
      7m 11s
    74. Disabling toolbars, resizing screens, and accidentally closed tabs
      7m 42s
    75. Identifying your wifi's weakest link
      7m 59s
    76. Setting up dual band speed on your router
      7m 36s
    77. Add your social media activity to your website
      8m 54s
    78. Using WordPress mobile to update on the go
      4m 48s
    79. Matching the header row on your spreadsheet files
      8m 20s
    80. Using a formula to merge first and last name columns
      5m 58s
    81. Using JoliDrive to browse cloud app data
      5m 11s
    82. Using JoliDrive on an iPad
      4m 31s
    83. Finding deals on eBay using misspelled listings
      4m 18s
    84. Searching for promotional and coupon codes online
      5m 52s
    85. Sending real postcards from your computer with Postagram
      4m 25s
    86. Using Postagram to send a real postcard from your smartphone
      3m 55s
    87. Getting to Inbox Zero
      11m 4s
    88. Using existing GMail labels with Mailbox
      3m 19s
    89. Adding 2-step authentication
      3m 39s
    90. Enabling in-app PIN codes
      3m 31s
    91. Accessing your digital movies
      5m 20s
    92. Copying movies onto a device
      3m 25s
    93. Using Genius Scan to scan your documents
      3m 34s
    94. Sending your scans
      2m 41s
    95. Using Acrobat to ink sign a PDF
      4m 49s
    96. Writing a letter of recommendation
      7m 49s
    97. Constructing a successful press release
      4m 48s
    98. Troubleshooting wireless security
      4m 48s
    99. Writing a claim letter
      5m 22s
    100. The best reasons to try online chat customer service
      5m 9s
    101. How to do a firmware update
      6m 34s
    102. Siri, your iPhone assistant
      4m 48s
    103. Writing an email that gets read
      4m 51s
    104. Writing an email that requires action
      2m 54s
    105. Your Blu-ray questions answered
      3m 50s
    106. Using LittleBit to photograph your goal progress
      3m 9s
    107. Exporting WordPress blog entries
      3m 28s
    108. Understanding how Office 365 works
      5m 9s
    109. Using Waze for crowdsourced GPS
      2m 58s
    110. Downloading your Facebook timeline
      3m 10s
    111. Scheduling email with Boomerang
      4m 24s
    112. Google Labs for Calendar
      2m 58s
    113. Finding missing songs in iTunes on your iPhone
      2m 10s
    114. Requesting your Twitter archive
      2m 59s
    115. Using Doodle for easy group scheduling
      4m 59s
    116. Easily remote to another computer with Join.me
      3m 47s
    117. Keyboard shortcuts for YouTube
      2m 58s
    118. Easily annotate images with Skitch
      6m 4s
    119. Blurring photos for posting on social networks
      6m 41s
    120. Migrating to Google Apps
      9m 31s
    121. Get your Google Calendar schedule by email every morning
      3m 3s
    122. Using supplemental To Do apps
      3m 43s

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