1 00:00:00,560 --> 00:00:08,230 Ethan at 10 base to use as correction CAPLE The specifications are different to the coaxial cable used 2 00:00:08,230 --> 00:00:10,240 in cable television. 3 00:00:10,270 --> 00:00:18,580 But the point I'm trying to make is coaxial cable running a baseband signal can only transmit or receive 4 00:00:18,610 --> 00:00:21,700 a single signal at any given time. 5 00:00:21,790 --> 00:00:29,020 Broadband uses coaxial cable that allows for multiple signals to be sent across the wire at any given 6 00:00:29,020 --> 00:00:29,810 time. 7 00:00:29,950 --> 00:00:32,310 Ethernet uses baseband signaling. 8 00:00:32,320 --> 00:00:37,010 In other words 10 base two or ten base five in the past. 9 00:00:37,090 --> 00:00:40,200 So in ten based to correction cable was used. 10 00:00:40,450 --> 00:00:47,590 But you can see connectors we use to connect devices to the network a BNC connector would connect the 11 00:00:47,590 --> 00:00:49,360 cable to the PC. 12 00:00:49,540 --> 00:00:51,430 Don't worry too much about this. 13 00:00:51,550 --> 00:00:56,830 This is just a bit of history so that you can understand why things are done in certain ways today. 14 00:00:57,070 --> 00:01:02,560 What's important to realize is that a single piece of cable would have been in-seat connectors which 15 00:01:02,560 --> 00:01:05,710 would allow you to connect devices to a single cable. 16 00:01:05,920 --> 00:01:12,760 Multiple devices were connected across a single cable and at the end you would have Terminators to stop 17 00:01:12,850 --> 00:01:17,750 signals bouncing back and gives an example of a terminator. 18 00:01:17,770 --> 00:01:24,400 So what it terminated did is essentially terminate the signal or destroy the signal when it got to the 19 00:01:24,400 --> 00:01:25,680 end of the wire. 20 00:01:25,720 --> 00:01:30,990 So when the signal is sent across the wire it shouldn't bounce back and cause collisions. 21 00:01:31,000 --> 00:01:36,290 So the Terminator would terminate the signal to ensure that it didn't bounce back. 22 00:01:36,340 --> 00:01:43,300 Once again the reason for doing this is because baseband is used baseband only allows a single signal 23 00:01:43,300 --> 00:01:47,280 to be sent across the wire or cable at any time. 24 00:01:47,410 --> 00:01:53,860 So we couldn't have a signal bouncing back and causing a collision hence terminate as we used. 25 00:01:53,860 --> 00:01:59,020 Now before we continue discussing the transmission of data in more detail let's talk about what a MAC 26 00:01:59,120 --> 00:02:08,200 addresses a Media Access Control address or MAC address also called a physical address is a unique identifier 27 00:02:08,470 --> 00:02:15,070 assigned to network interfaces and MAC addresses a layer to address identifying a network interface 28 00:02:15,070 --> 00:02:16,550 card or MC. 29 00:02:16,660 --> 00:02:19,600 It is typically boltin by the manufacturer. 30 00:02:19,600 --> 00:02:28,360 In other words it's Boente in to the network card Bhave Nic manufacturer and it's 48 bits in length 31 00:02:28,830 --> 00:02:32,070 the 48 bits are divided into two portions. 32 00:02:32,230 --> 00:02:38,100 The UI portion is 24 bits in length and the station address is also 24 bits in length. 33 00:02:38,120 --> 00:02:49,360 The UI organizational unique identifier identifies a vendor such as Cisco or HP or Dell or other vendors 34 00:02:49,630 --> 00:02:54,470 that manufacture network devices or PCs or servers. 35 00:02:54,520 --> 00:02:57,320 Each manufacturer is assigned and why. 36 00:02:57,430 --> 00:03:04,780 And each vendor in turn can create and assign and station addresses to Network Interface Cards the station 37 00:03:04,780 --> 00:03:07,270 addresses should be unique. 38 00:03:07,270 --> 00:03:14,000 Now they should be unique because there have been cases where addresses have been duplicated by manufacturers. 39 00:03:14,140 --> 00:03:19,540 So you may end up having a network with duplicate MAC addresses which causes a lot of problems in an 40 00:03:19,540 --> 00:03:25,680 Ethernet environment in an Ethernet environment on a segment or a piece of cable. 41 00:03:25,690 --> 00:03:29,920 We're assuming that all devices have a unique MAC address. 42 00:03:29,950 --> 00:03:33,900 It's also possible in software to change device MAC addresses. 43 00:03:34,090 --> 00:03:43,230 So my interface card as an example I can go to properties go to configuration selected vaunts I can 44 00:03:43,230 --> 00:03:50,060 then go to a locally administrated addresses and then I can change the valley so I could make it quadruple 45 00:03:50,060 --> 00:03:54,750 a quadruple be quadruple see and click ok. 46 00:03:56,110 --> 00:04:03,790 Opening ACMD prompt and tapping IP config for special and then scrolling up I'll be able to see that 47 00:04:03,790 --> 00:04:12,230 my physical MAC address is now set to a b c I've just changed my MAC address from the phone to in the 48 00:04:12,310 --> 00:04:15,960 address set by the manufacturer to something else. 49 00:04:15,970 --> 00:04:23,080 Now if I did that on multiple PCs or multiple devices I would be causing an issue with duplicate MAC 50 00:04:23,080 --> 00:04:24,230 addresses. 51 00:04:24,250 --> 00:04:28,190 So once again the first portion of a MAC address is the UI. 52 00:04:28,540 --> 00:04:34,050 And the second portion is a unique value assigned by a manufacturer. 53 00:04:34,090 --> 00:04:40,070 So on my network card I'll set it back to the default. 54 00:04:40,110 --> 00:04:47,610 So now when I run IP config less you'll notice the built in MAC address on my local area connection 55 00:04:48,000 --> 00:04:52,520 uses the unique value assigned by the manufacturer. 56 00:04:52,620 --> 00:04:54,770 Why Asharq has a nice tool to look at. 57 00:04:54,780 --> 00:04:56,210 Oh you like coats. 58 00:04:56,370 --> 00:05:03,610 So I've just added the 0 0 0 1 E6 and that should list the manufacturer for that MAC address. 59 00:05:03,720 --> 00:05:11,850 In this case you can see it's HP some MAC addresses that start with triple 0 1 6 hp MAC addresses. 60 00:05:11,880 --> 00:05:16,410 I can also look on the dribbly Web site to see similar information. 61 00:05:16,410 --> 00:05:21,930 Notice that both E-6 and IE 7 codes are manufactured by HP. 62 00:05:21,930 --> 00:05:29,190 There's a long list of different codes and you'll be able to see which codes are associated with which 63 00:05:29,280 --> 00:05:29,720 vendor.