1 00:00:06,640 --> 00:00:12,490 Now we've been told to configure of one with the lost IP address in the that subnet. 2 00:00:12,500 --> 00:00:19,640 Now this is the subnet that we concentrating on initially so let's start with that subnet. 3 00:00:19,770 --> 00:00:21,970 The way you work out first. 4 00:00:21,990 --> 00:00:25,430 Lost and broadcast addresses as follows. 5 00:00:25,770 --> 00:00:32,310 The network has the host portion populated with binary zeros. 6 00:00:32,310 --> 00:00:35,470 So notice whose portion is all zeros. 7 00:00:35,640 --> 00:00:43,590 The first host has the host portion populated with binary zeros except for the lost but which is set 8 00:00:43,600 --> 00:00:45,300 to a one in binary. 9 00:00:45,630 --> 00:00:53,910 So that's the first host in the subnet The Lost host in the subnet as the host portion populated with 10 00:00:53,970 --> 00:01:02,310 binary ones except for the lost but which is set to binary 0 and I'll show you in a moment what that 11 00:01:02,310 --> 00:01:06,970 is but it's easier to work out the broadcast address first. 12 00:01:07,350 --> 00:01:13,500 So the broadcast address equals that subnet 13 00:01:16,960 --> 00:01:21,690 and the host portion is populated with binary ones. 14 00:01:22,150 --> 00:01:26,190 So it's 1 1 followed by 4 ones. 15 00:01:26,190 --> 00:01:31,510 Now you can work this out by saying 32 plus 16 plus eight plus four plus two plus one. 16 00:01:31,600 --> 00:01:39,040 But I find it easier to do the following if this is set to 1 and everything else is set to zeros so 17 00:01:39,040 --> 00:01:48,130 it looks like this that equals 64 one less than that equals 63. 18 00:01:48,160 --> 00:01:52,060 So if you asked for something like this what is the broadcast address. 19 00:01:52,060 --> 00:01:59,190 Have a look at the next subnet and subtract one to get to the broadcast address of the previous subnet. 20 00:01:59,350 --> 00:02:03,460 The next subnet is 1 9 2 1 6 8 1 64. 21 00:02:03,460 --> 00:02:08,980 The broadcast address of the previous subnet is that subnet minus 1. 22 00:02:08,980 --> 00:02:13,320 So in other words it's 63 and then this is 62. 23 00:02:13,360 --> 00:02:21,750 So for this subnet that's the network and first host This is the lost and broadcast address. 24 00:02:21,940 --> 00:02:32,440 Second lost which we need for this switch is essentially one less than that can work out the binary 25 00:02:32,890 --> 00:02:36,670 but it may be easier just to subtract one from the decimal. 26 00:02:36,670 --> 00:02:38,200 So that's 61. 27 00:02:38,620 --> 00:02:41,890 And the third lost is one less than that which is 60 28 00:02:44,910 --> 00:02:50,770 so we now know the network the first host the broadcast the lost host. 29 00:02:50,820 --> 00:02:54,420 Second lost host and third lost host. 30 00:02:54,420 --> 00:03:01,650 Easiest way to work this out is to work out to the network and then work out the next network one less 31 00:03:01,650 --> 00:03:08,730 than the next network gives you the broadcast address for the current subnet and then you can just subtract 32 00:03:08,730 --> 00:03:11,880 one from that to get to the lost host. 33 00:03:11,910 --> 00:03:18,330 Second lost host and third lost host first host is equal to the network portion plus 1. 34 00:03:18,330 --> 00:03:20,340 So they are our values. 35 00:03:20,340 --> 00:03:26,590 That means we can now configure this router with the lost IP address in the subnet. 36 00:03:26,700 --> 00:03:34,350 So currently on this router it only has a loop back interface configured it it doesn't have an IP address 37 00:03:34,350 --> 00:03:35,400 configured on gigabit. 38 00:03:35,430 --> 00:03:37,700 0 0 0. 39 00:03:37,710 --> 00:03:48,570 Remember the network 1 9 2 1 6 8 1.0 slash 26 has two bits that are part of the network portion two 40 00:03:48,570 --> 00:03:49,830 binary bits. 41 00:03:50,130 --> 00:03:54,350 Looks like that which equals 192. 42 00:03:55,050 --> 00:03:58,270 So we can configure the gigabit. 43 00:03:58,330 --> 00:04:09,610 0 0 0 interface with an IP address of 1 8 2 1 6 8 1 62 because that's the last IP address in the subnet. 44 00:04:09,610 --> 00:04:15,940 So 62 and the mask is 2 4 5 2 4 5 2 4 5 1 92. 45 00:04:16,390 --> 00:04:20,650 And that's because these two bits are part of the network. 46 00:04:20,650 --> 00:04:28,710 So we've got 255 255 255 two bits there which equates to 192. 47 00:04:29,060 --> 00:04:36,220 So show IP interface brief we can now paying our local IP address. 48 00:04:36,220 --> 00:04:41,530 The switch needs to be configured with the second a lost IP address in the subnet. 49 00:04:41,590 --> 00:04:47,770 Per these instructions so configure the switches with the second lost IP address and then the DHB servers 50 00:04:47,770 --> 00:04:50,440 with the third lost IP address. 51 00:04:50,650 --> 00:04:53,440 So again he has I'll switch 52 00:04:56,220 --> 00:04:57,050 I'll give it a name. 53 00:04:57,150 --> 00:05:09,880 Switch one interface of Ilan one no shut IP address 1 9 2 1 6 8 1 and the next IP address that we can 54 00:05:09,880 --> 00:05:16,200 use is 60 1 2 4 5 2 4 5 2 4 5 1 92. 55 00:05:16,490 --> 00:05:27,940 So show IP interface brief that's the IP address of the switch can the switch now ping the router yes 56 00:05:27,940 --> 00:05:34,450 it can switch has been successfully configured router has been successfully configured let's configure 57 00:05:34,450 --> 00:05:42,340 the DHB server so on the Ethernet interface we going to configure a static IP address of 1 9 2 1 6 8 58 00:05:42,340 --> 00:05:50,740 1 and the IP address will be 60 in this example third lost IP address subnet Moscow will be 2 4 5 2 59 00:05:50,740 --> 00:05:52,900 4 5 2 4 5 1 92. 60 00:05:52,990 --> 00:06:03,250 Now the default gateway will be the router 1 9 2 1 6 8 1 and the Rada once again has IP address 62 so 61 00:06:03,320 --> 00:06:13,240 62 DNS server and this example will be 8 today to today to date this is the internet DNS server it's 62 00:06:13,240 --> 00:06:22,700 configured with DNS names for Cisco dot com and Facebook dot com so the server has been configured. 63 00:06:22,700 --> 00:06:25,610 Can we ping the switch. 64 00:06:25,610 --> 00:06:26,810 Yes we can. 65 00:06:26,810 --> 00:06:27,950 What about the router. 66 00:06:28,310 --> 00:06:30,130 Yes we can. 67 00:06:30,140 --> 00:06:37,820 So we've configured IP addresses and default gateways on the network devices. 68 00:06:37,820 --> 00:06:42,980 Now one thing I still need to do on the switch is specify a default gateway which will be the router 69 00:06:43,490 --> 00:06:46,360 Rod it has IP address 62 70 00:06:49,080 --> 00:06:59,470 so again the switch can ping the router we've finished configuring the switch now on the DHB server 71 00:06:59,560 --> 00:07:09,640 we need to configure a DHB pool default gateway is going to be the router 62 DNS server is going to 72 00:07:09,640 --> 00:07:18,160 be the Google DNS server and we can allocate IP addresses from 1 9 2 1 6 8 1 2 1. 73 00:07:18,160 --> 00:07:24,080 So from the first ip address in the subnet to a number that we decide. 74 00:07:24,340 --> 00:07:30,790 So we could as an example allocate 100 IP addresses so I'll save that. 75 00:07:30,830 --> 00:07:38,330 So we've specified the pull name default gateway DNS server starting IP address in the pool and the 76 00:07:38,330 --> 00:07:44,610 number of IP addresses that can be allocated now can I specify a hundred hosted addresses the answer 77 00:07:44,610 --> 00:07:53,400 is no I should actually specify only something like 50 because of the subnet only supports 62 IP addresses 78 00:07:54,270 --> 00:08:00,930 so remember the formula 2 to the power of something which is the number of but minus 2 gives you the 79 00:08:00,930 --> 00:08:04,230 number of hosts that are supported in a subnet. 80 00:08:04,230 --> 00:08:07,030 Yeah we've got six binary bits. 81 00:08:07,170 --> 00:08:09,180 So two to the power of six. 82 00:08:09,240 --> 00:08:15,380 That's the number of bits in the WHO's portion what's two to the power of six two to the power four 83 00:08:15,380 --> 00:08:19,880 is sixteen two to the power of five equals thirty two. 84 00:08:20,030 --> 00:08:31,970 Two to the power of six equals 64 so 64 minus two gives us sixty two hosts that are supported in a subnet 85 00:08:32,570 --> 00:08:39,740 but we want to allocate some of those IP addresses to network devices so we don't want to allocate the 86 00:08:39,770 --> 00:08:50,540 full submit to the DHB server we'll only allocate a portion of the addresses to hosts via DCP so on 87 00:08:50,540 --> 00:08:59,870 P.S. One does the piece you have an IP address yes it does it's been allocated 1 on 2 1 6 8 1 dot 3 88 00:09:00,470 --> 00:09:04,520 cannot ping the default gateway yes it can. 89 00:09:04,520 --> 00:09:14,570 P.S. 1 as an example IP config it's also been allocated an IP address 1 9 2 1 6 8 1 2 2 cannot ping 90 00:09:15,310 --> 00:09:21,370 its default gateway yes it can and on P.C. to do something similar. 91 00:09:21,680 --> 00:09:31,790 IP address has been allocated and it can ping its a default gateway so we've successfully configured 92 00:09:33,080 --> 00:09:34,490 subnet 1. 93 00:09:34,790 --> 00:09:40,520 Now we need to configure the serial link and then once I've done that I'll check whether these devices 94 00:09:40,520 --> 00:09:44,630 can access devices on the Internet and then I'll configure the other subnets.