1 00:00:06,810 --> 00:00:10,210 - Back in 1997, someone had this awesome idea 2 00:00:10,210 --> 00:00:13,280 to take wired ethernet and make it wireless. 3 00:00:13,280 --> 00:00:18,210 And the term wireless local area network was born or WLAN. 4 00:00:18,210 --> 00:00:21,136 It's an IEEE standard 802.11. 5 00:00:21,136 --> 00:00:26,136 And in 1999, 802.11b is what became popularized 6 00:00:26,850 --> 00:00:28,860 because prices were coming down 7 00:00:28,860 --> 00:00:31,520 and you could buy a PCMCIA card 8 00:00:31,520 --> 00:00:33,330 and join Wi-Fi networks. 9 00:00:33,330 --> 00:00:34,200 And it was pretty neat 10 00:00:34,200 --> 00:00:35,360 'cause you didn't need to have this 11 00:00:35,360 --> 00:00:38,290 wired ethernet cable coming into your computer. 12 00:00:38,290 --> 00:00:39,480 It was a little bit slower, 13 00:00:39,480 --> 00:00:41,813 but it was quite a bit more convenient. 14 00:00:43,420 --> 00:00:46,940 Common deployment methodologies or thoughts here. 15 00:00:46,940 --> 00:00:48,810 So small office, home office, 16 00:00:48,810 --> 00:00:50,010 coffee shop, et cetera, 17 00:00:50,010 --> 00:00:51,810 you have a wireless LAN router, 18 00:00:51,810 --> 00:00:54,430 client connects to that wireless LAN. 19 00:00:54,430 --> 00:00:57,290 It's wireless from client to the router, 20 00:00:57,290 --> 00:00:59,770 which is then wired up towards the internet. 21 00:00:59,770 --> 00:01:01,600 Over in the enterprise side of things, 22 00:01:01,600 --> 00:01:02,970 it's pretty common to see 23 00:01:02,970 --> 00:01:06,070 a wireless access point that is bridging 24 00:01:06,070 --> 00:01:09,600 layer two into a switched environment 25 00:01:09,600 --> 00:01:11,670 and then routed out to the internet. 26 00:01:11,670 --> 00:01:13,860 The key point here, though, 27 00:01:13,860 --> 00:01:17,820 it is still IP, it's still ethernet networking. 28 00:01:17,820 --> 00:01:18,653 What's the difference 29 00:01:18,653 --> 00:01:21,210 between attacking a wired ethernet network 30 00:01:21,210 --> 00:01:23,260 and a wireless ethernet network? 31 00:01:23,260 --> 00:01:25,060 It's simply that connection medium. 32 00:01:25,060 --> 00:01:25,893 It's still IP. 33 00:01:25,893 --> 00:01:27,140 We still have MAC addresses. 34 00:01:27,140 --> 00:01:28,750 Layer two is still the same. 35 00:01:28,750 --> 00:01:30,950 It's the physical connectivity that changes. 36 00:01:32,500 --> 00:01:36,110 IEEE standards have grown and evolved over time. 37 00:01:36,110 --> 00:01:39,600 Started at 802.11b back in 1999, 38 00:01:39,600 --> 00:01:43,330 went up to 802.11a, g, n, ac, 39 00:01:43,330 --> 00:01:46,250 and now latest 802.11ax, 40 00:01:46,250 --> 00:01:49,500 which gives us very fast wireless connectivity 41 00:01:49,500 --> 00:01:51,720 with a range of frequencies. 42 00:01:51,720 --> 00:01:54,110 So we are still sitting in ISM bands here, 43 00:01:54,110 --> 00:01:58,120 2.4 gig and 5.8 gig in order to comply 44 00:01:58,120 --> 00:02:00,700 with licensing worldwide 45 00:02:00,700 --> 00:02:04,300 or rather frequency allocations worldwide. 46 00:02:04,300 --> 00:02:07,000 Wireless LAN SSIDs. 47 00:02:07,000 --> 00:02:11,006 So the name of a wireless LAN will be an SSID. 48 00:02:11,006 --> 00:02:13,770 SSID stands for service set identifier, 49 00:02:13,770 --> 00:02:18,050 and it distinguishes wireless LANs in the same airspace. 50 00:02:18,050 --> 00:02:19,300 There is nothing stopping me 51 00:02:19,300 --> 00:02:21,010 from having 10 wireless LANs 52 00:02:21,010 --> 00:02:22,890 surrounding me right now. 53 00:02:22,890 --> 00:02:24,350 And they could all have different names 54 00:02:24,350 --> 00:02:26,300 and I could pick the one I want to connect to. 55 00:02:26,300 --> 00:02:28,670 So we have overlapping airspace, right? 56 00:02:28,670 --> 00:02:31,770 So whatever channel this router chooses to use 57 00:02:31,770 --> 00:02:33,920 could overlap with the channel on this one. 58 00:02:33,920 --> 00:02:36,840 So it's a contested medium, 59 00:02:36,840 --> 00:02:38,480 the air that is. 60 00:02:38,480 --> 00:02:41,710 SSID are 32 bites and often human readable, 61 00:02:41,710 --> 00:02:43,350 though they don't have to be. 62 00:02:43,350 --> 00:02:45,849 However, if you're gonna type in that SSID, 63 00:02:45,849 --> 00:02:47,943 it's probably gotta be ASCII. 64 00:02:49,330 --> 00:02:53,180 A BSSID distinguishes access points 65 00:02:53,180 --> 00:02:55,920 on these same wireless LAN. 66 00:02:55,920 --> 00:02:57,930 The distinguishing point here 67 00:02:57,930 --> 00:03:01,080 is the MAC address of the access point itself. 68 00:03:01,080 --> 00:03:02,740 So I have an example of that here. 69 00:03:02,740 --> 00:03:05,690 We have the same wireless land SSID 70 00:03:05,690 --> 00:03:07,740 with two separate access points. 71 00:03:07,740 --> 00:03:11,260 They would have different BSSIDs. 72 00:03:11,260 --> 00:03:13,550 That BSSID would be the MAC address, 73 00:03:13,550 --> 00:03:16,713 but using the same wireless LAN name. 74 00:03:18,880 --> 00:03:21,030 Infrastructure mode versus ad hoc mode. 75 00:03:21,030 --> 00:03:22,080 In infrastructure mode, 76 00:03:22,080 --> 00:03:24,150 you're going to connect to an access point, 77 00:03:24,150 --> 00:03:25,890 which is part of the infrastructure. 78 00:03:25,890 --> 00:03:27,610 And it's going to give you layer two, 79 00:03:27,610 --> 00:03:31,270 layer three, layer seven connectivity. 80 00:03:31,270 --> 00:03:33,940 Ad hoc mode will also give you layer two 81 00:03:33,940 --> 00:03:35,070 through seven connectivity. 82 00:03:35,070 --> 00:03:37,920 However, you are connecting point-to-point. 83 00:03:37,920 --> 00:03:39,790 With access point to client, 84 00:03:39,790 --> 00:03:42,070 you have what is an access point 85 00:03:42,070 --> 00:03:43,960 and then the client connecting to it. 86 00:03:43,960 --> 00:03:45,980 In ad hoc mode, there is no access point. 87 00:03:45,980 --> 00:03:48,983 It's two devices talking directly to each other. 88 00:03:50,800 --> 00:03:52,050 Security algorithms. 89 00:03:52,050 --> 00:03:54,540 If this was all unencrypted, 90 00:03:54,540 --> 00:03:56,980 open networks, no authentication, 91 00:03:56,980 --> 00:03:59,330 there would be so much hacking going on. 92 00:03:59,330 --> 00:04:00,560 (laughs) 93 00:04:00,560 --> 00:04:02,440 'Cause the wireless networking 94 00:04:02,440 --> 00:04:04,450 is so prevalent these days, 95 00:04:04,450 --> 00:04:06,470 anywhere you go, you open your laptop 96 00:04:06,470 --> 00:04:08,780 and you see 20 to 30 wireless networks 97 00:04:08,780 --> 00:04:10,560 that you can connect to. 98 00:04:10,560 --> 00:04:11,650 The majority of them 99 00:04:11,650 --> 00:04:13,830 are gonna have some form of security employed. 100 00:04:13,830 --> 00:04:17,100 It started with WEP, which was particularly insecure. 101 00:04:17,100 --> 00:04:18,379 We're gonna talk about WEP, 102 00:04:18,379 --> 00:04:22,800 and WPA, WPA2, and 3 in a coming lesson. 103 00:04:22,800 --> 00:04:25,420 As we move down the list here, 104 00:04:25,420 --> 00:04:27,943 we become more and more secure.