1 1 00:00:00,310 --> 00:00:01,760 Captive portal. 2 2 00:00:01,760 --> 00:00:04,350 In this lesson, we're going to discuss captive portals 3 3 00:00:04,350 --> 00:00:06,920 and some issues you may experience when you're using them. 4 4 00:00:06,920 --> 00:00:09,270 First, what is a captive portal? 5 5 00:00:09,270 --> 00:00:11,110 Well, a captive portal is a webpage 6 6 00:00:11,110 --> 00:00:12,910 that's access from your web browser, 7 7 00:00:12,910 --> 00:00:14,980 and it's going to be displayed to newly connected users 8 8 00:00:14,980 --> 00:00:17,820 of a wireless network before they're granted broader access 9 9 00:00:17,820 --> 00:00:19,420 to network resources. 10 10 00:00:19,420 --> 00:00:21,120 Captive portals are commonly going to be used 11 11 00:00:21,120 --> 00:00:23,390 to present a landing page or a login page, 12 12 00:00:23,390 --> 00:00:25,660 which is going to require authentication, payment 13 13 00:00:25,660 --> 00:00:27,920 or acceptance of an end user license agreement 14 14 00:00:27,920 --> 00:00:29,830 or something like acceptable use policies, 15 15 00:00:29,830 --> 00:00:32,200 survey completion, or some other kind of information 16 16 00:00:32,200 --> 00:00:34,180 we're trying to collect from you before we allow you 17 17 00:00:34,180 --> 00:00:36,480 to get onto our network and our resources. 18 18 00:00:36,480 --> 00:00:38,820 Now, these captive portals are commonly used at places 19 19 00:00:38,820 --> 00:00:41,270 like hotels, restaurants, airports, 20 20 00:00:41,270 --> 00:00:42,870 and other places that give you free 21 21 00:00:42,870 --> 00:00:45,821 or paid wireless networks for you to connect to and use. 22 22 00:00:45,821 --> 00:00:48,110 In general, captive portals are implemented 23 23 00:00:48,110 --> 00:00:51,340 by using an HTTP redirect, an ICMP redirect, 24 24 00:00:51,340 --> 00:00:53,000 or a DNS redirect. 25 25 00:00:53,000 --> 00:00:55,640 We're going to talk about all three of those in this lesson. 26 26 00:00:55,640 --> 00:00:58,200 Now, when a user attempts to log into a wireless network 27 27 00:00:58,200 --> 00:01:00,740 and the captive portal doesn't redirect them properly, 28 28 00:01:00,740 --> 00:01:03,030 it can be a really frustrating experience. 29 29 00:01:03,030 --> 00:01:05,040 I personally had this happen to me a lot, 30 30 00:01:05,040 --> 00:01:07,930 but luckily, I know how to troubleshoot and fix this issue. 31 31 00:01:07,930 --> 00:01:10,220 And after this video, you will too. 32 32 00:01:10,220 --> 00:01:12,260 Now, for example, I was flying home recently 33 33 00:01:12,260 --> 00:01:15,290 on a Delta flight and they use a captive portal system. 34 34 00:01:15,290 --> 00:01:17,740 When you connect to the Delta Wi-Fi network on the plane, 35 35 00:01:17,740 --> 00:01:18,850 it's supposed to redirect you 36 36 00:01:18,850 --> 00:01:20,540 to the captive portals login page 37 37 00:01:20,540 --> 00:01:22,160 so you can enter your account information 38 38 00:01:22,160 --> 00:01:25,020 so you can access the internet if you're a SkyMiles member. 39 39 00:01:25,020 --> 00:01:26,990 Now this didn't work on my MacBook Pro though. 40 40 00:01:26,990 --> 00:01:29,210 So I had to start begin troubleshooting this issue 41 41 00:01:29,210 --> 00:01:31,520 and figure out what was causing the problem. 42 42 00:01:31,520 --> 00:01:33,300 It could have been any of the three redirect methods, 43 43 00:01:33,300 --> 00:01:35,160 cause I didn't know which one they were using. 44 44 00:01:35,160 --> 00:01:37,370 So let's say first I went and tried to see 45 45 00:01:37,370 --> 00:01:39,380 if they used an HTTP redirect. 46 46 00:01:39,380 --> 00:01:41,030 With an HTTP redirect, 47 47 00:01:41,030 --> 00:01:44,130 all traffic is redirected to a web server that they control. 48 48 00:01:44,130 --> 00:01:46,490 And then this web server redirects the clients 49 49 00:01:46,490 --> 00:01:50,990 to the captive portal using an HTTP status code of 302. 50 50 00:01:50,990 --> 00:01:52,680 In the case of this in-flight Wi-Fi, 51 51 00:01:52,680 --> 00:01:54,010 that is not what they were using 52 52 00:01:54,010 --> 00:01:56,630 and so I moved on to my troubleshooting efforts. 53 53 00:01:56,630 --> 00:01:59,780 Second, I looked to see if they were using ICMP packets 54 54 00:01:59,780 --> 00:02:01,830 to redirect me to a captive portal. 55 55 00:02:01,830 --> 00:02:04,150 Now, ICMP is a network protocol that's used 56 56 00:02:04,150 --> 00:02:06,630 to send error messages and operational information 57 57 00:02:06,630 --> 00:02:08,340 indicating the success or failure 58 58 00:02:08,340 --> 00:02:10,760 of communicating with another IP address. 59 59 00:02:10,760 --> 00:02:13,380 With an ICMP redirect, it's not a very common way 60 60 00:02:13,380 --> 00:02:16,100 to do captive portals these days, at least in my experience. 61 61 00:02:16,100 --> 00:02:18,440 And again, I found that they were not using that 62 62 00:02:18,440 --> 00:02:20,310 inside of the in-flight Wi-FI, 63 63 00:02:20,310 --> 00:02:22,500 and so I moved on to step three. 64 64 00:02:22,500 --> 00:02:24,780 Step three is probably your most common type. 65 65 00:02:24,780 --> 00:02:27,610 And this is what's known as a DNS redirection. 66 66 00:02:27,610 --> 00:02:30,110 Now, when the client joins the inflight Wi-Fi 67 67 00:02:30,110 --> 00:02:32,630 on board the aircraft, the client gets an IP address, 68 68 00:02:32,630 --> 00:02:34,340 a subnet mask, a gateway, 69 69 00:02:34,340 --> 00:02:36,830 and a DNS server IP from the network. 70 70 00:02:36,830 --> 00:02:38,440 Now this is all handed out to you 71 71 00:02:38,440 --> 00:02:40,330 from the onboard DHCP server 72 72 00:02:40,330 --> 00:02:42,140 when you connect to the network. 73 73 00:02:42,140 --> 00:02:44,300 Now, when the client opens up a web browser 74 74 00:02:44,300 --> 00:02:47,910 to connect to a website like deontrain.com or google.com, 75 75 00:02:47,910 --> 00:02:49,160 the client is going to be redirected 76 76 00:02:49,160 --> 00:02:50,680 to the onboard DNS server 77 77 00:02:50,680 --> 00:02:53,790 and then redirected to that captive portal page. 78 78 00:02:53,790 --> 00:02:55,610 This is exactly what the in-flight Wi-Fi 79 79 00:02:55,610 --> 00:02:56,730 is attempting to use, 80 80 00:02:56,730 --> 00:02:59,440 but it wasn't working on my MacBook Pro. 81 81 00:02:59,440 --> 00:03:00,890 Now, why is that? 82 82 00:03:00,890 --> 00:03:02,020 Well, the issue was, 83 83 00:03:02,020 --> 00:03:04,450 my client was already configured to use DNS 84 84 00:03:04,450 --> 00:03:06,350 from a static server that I assigned 85 85 00:03:06,350 --> 00:03:09,150 and not the onboard Wi-Fi's DNS server. 86 86 00:03:09,150 --> 00:03:13,080 Instead, I always use my DNS server as 8.8.8.8, 87 87 00:03:13,080 --> 00:03:15,980 which is Google's DNS server because I trust that one. 88 88 00:03:15,980 --> 00:03:18,750 So I was configured to use Google's DNS server, 89 89 00:03:18,750 --> 00:03:20,290 not the onboard DNS server, 90 90 00:03:20,290 --> 00:03:22,050 and therefore it couldn't redirect me 91 91 00:03:22,050 --> 00:03:23,560 to their captive portal. 92 92 00:03:23,560 --> 00:03:26,070 So I quickly disconnected from Wi-Fi, 93 93 00:03:26,070 --> 00:03:29,170 I cleared out my saved DNS setting of 8.8.8.8, 94 94 00:03:29,170 --> 00:03:32,150 and I set it automatically be configured over DHCP. 95 95 00:03:32,150 --> 00:03:34,710 Then I reconnected to the onboard Wi-Fi. 96 96 00:03:34,710 --> 00:03:36,960 Immediately, I was forwarded to the captive portal 97 97 00:03:36,960 --> 00:03:38,970 and I was able to get online and surf the web 98 98 00:03:38,970 --> 00:03:41,610 at 36,000 feet over the Atlantic Ocean. 99 99 00:03:41,610 --> 00:03:44,060 Isn't modern technology just wonderful? 100 100 00:03:44,060 --> 00:03:46,710 So, what are some other common captive portal issues 101 101 00:03:46,710 --> 00:03:48,370 that you might experience? 102 102 00:03:48,370 --> 00:03:49,960 Well, if you're dealing with a smartphone 103 103 00:03:49,960 --> 00:03:51,660 like an Apple or an Android device, 104 104 00:03:51,660 --> 00:03:53,200 especially with Apple devices, 105 105 00:03:53,200 --> 00:03:55,430 sometimes these things don't automatically load up 106 106 00:03:55,430 --> 00:03:58,240 the captive page upon connecting to the wireless network. 107 107 00:03:58,240 --> 00:04:00,840 If this occurs, you should first open up a web browser 108 108 00:04:00,840 --> 00:04:04,180 and try to go to any site like google.com or facebook.com, 109 109 00:04:04,180 --> 00:04:06,490 something you know should always be up and available. 110 110 00:04:06,490 --> 00:04:10,330 This should cause the captive portals HTTP or DNS redirects 111 111 00:04:10,330 --> 00:04:11,770 to take over and then present you 112 112 00:04:11,770 --> 00:04:13,800 with a captive portal login page. 113 113 00:04:13,800 --> 00:04:15,230 Now, if this doesn't work, 114 114 00:04:15,230 --> 00:04:17,330 then you're going to need to check your IP configuration 115 115 00:04:17,330 --> 00:04:20,360 of your smartphone and determine what the default gateway is 116 116 00:04:20,360 --> 00:04:22,390 for that wireless network you're connected to. 117 117 00:04:22,390 --> 00:04:25,880 Then you could type that IP address into your web browser. 118 118 00:04:25,880 --> 00:04:27,460 This will force load the cactus portal 119 119 00:04:27,460 --> 00:04:29,030 in most cases as well. 120 120 00:04:29,030 --> 00:04:31,580 Now, the same thing can happen on your laptops as well. 121 121 00:04:31,580 --> 00:04:33,440 And if it does, I tend to follow 122 122 00:04:33,440 --> 00:04:35,670 the same three-step troubleshooting process. 123 123 00:04:35,670 --> 00:04:37,440 First, I open up a web browser 124 124 00:04:37,440 --> 00:04:38,980 and I try to go to any website 125 125 00:04:38,980 --> 00:04:41,490 like google.com or facebook.com. 126 126 00:04:41,490 --> 00:04:43,310 Second, if that doesn't work, 127 127 00:04:43,310 --> 00:04:44,680 I determine what the default gateway 128 128 00:04:44,680 --> 00:04:48,720 for the wireless network is, and I enter http:// 129 129 00:04:48,720 --> 00:04:51,250 and the IP address for that default gateway. 130 130 00:04:51,250 --> 00:04:52,880 Then I hit enter. 131 131 00:04:52,880 --> 00:04:54,530 Third, If that doesn't work, 132 132 00:04:54,530 --> 00:04:56,670 I verify my DNS server IPs. 133 133 00:04:56,670 --> 00:04:58,310 And I make sure that it's not set to something 134 134 00:04:58,310 --> 00:05:02,470 like 8.8.8.8 manually and instead I turn on DHCP 135 135 00:05:02,470 --> 00:05:05,600 for it to allow me to auto configure my DNS on my laptop 136 136 00:05:05,600 --> 00:05:07,460 to connect to their wireless network. 137 137 00:05:07,460 --> 00:05:09,340 Then I reattempt step number one 138 138 00:05:09,340 --> 00:05:12,130 by opening up a web browser and going to any website again. 139 139 00:05:12,130 --> 00:05:13,870 Usually, these three steps will solve 140 140 00:05:13,870 --> 00:05:15,420 most of the issues you're going to come across 141 141 00:05:15,420 --> 00:05:16,593 with captive portals.