1 00:00:06,370 --> 00:00:12,800 Okay, so the next subnet is 1 9 2 1 6 8 1 64 slash 26. 2 00:00:12,800 --> 00:00:19,540 I'll copy the previous example but remember this is actually a different subnet now. 3 00:00:19,540 --> 00:00:29,900 The subnet address is slash 64, so we'll need to update these values in the last octet. 4 00:00:30,010 --> 00:00:37,420 So to work out the first host you simply add 1 to the subnet portion, subnet portion is 64. 5 00:00:37,510 --> 00:00:40,880 So 1 added to that is 65. 6 00:00:41,050 --> 00:00:44,830 The next subnet is 128. 7 00:00:44,830 --> 00:00:49,300 So going back to our original example, this is the second subnet. 8 00:00:49,300 --> 00:00:52,890 This is the third subnet, 128. 9 00:00:52,940 --> 00:00:59,320 That means that the broadcast for the subnet is 127 because 128 minus one equals 127. 10 00:00:59,770 --> 00:01:09,940 This is the next subnet minus one gives us our broadcast for the current subnet, last IP address in the 11 00:01:09,940 --> 00:01:11,820 subnet is 126. 12 00:01:11,830 --> 00:01:13,990 Next one is 125. 13 00:01:13,990 --> 00:01:17,220 Next one is 124. 14 00:01:17,260 --> 00:01:24,360 So there is our subnet broadcast for second last host and third last host. 15 00:01:24,400 --> 00:01:26,230 I haven't rechecked the binary. 16 00:01:26,230 --> 00:01:28,280 You could do that if you wanted to. 17 00:01:28,300 --> 00:01:34,450 I'm simply using a quick method to work out the IP addresses so this router needs to be configured with 18 00:01:34,450 --> 00:01:47,440 the first IP address on the serial interface, so interface serial 0 1 0, no shut, IP address 1 9 2 1 6 19 00:01:47,440 --> 00:01:53,670 8 165 uses that subnet mask. 20 00:01:53,770 --> 00:02:01,420 So again it's just one more than the broadcast address, show IP interface brief there's the IP address 21 00:02:01,450 --> 00:02:11,920 on the serial interface on the Internet router, we need to use one less than the next subnet so 127, show 22 00:02:11,920 --> 00:02:23,160 IP interface brief on the first serial interface, interface serial 0 1 0, no shut, IP address 1 9 2 1 6 23 00:02:23,160 --> 00:02:36,440 8 1 126 with the subnet mask, 127 is the broadcast one less than that gives us our last IP address, So 24 00:02:36,440 --> 00:02:40,880 can we ping 1 9 2 1 6 8 1 65? Yes, we can. 25 00:02:41,150 --> 00:02:42,760 So that's great. 26 00:02:42,920 --> 00:02:51,230 We have IP connectivity between this router and the Internet router and notice an OSPF neighbour relationship 27 00:02:51,230 --> 00:02:58,910 has come up, the routers were pre-configured with OSPF, so hopefully this router can now ping the 28 00:02:58,910 --> 00:03:10,070 DNS server on the Internet and notice it can. On PC 1, can it ping the DNS server? Yes, it can. 29 00:03:10,310 --> 00:03:20,990 If I trace to the DNS server traffic is going to router 1 on the Ethernet interface then it's going 30 00:03:20,990 --> 00:03:25,580 to the Internet router on the serial interface then to the Internet. 31 00:03:25,580 --> 00:03:33,500 The reason it works is, this router has been pre-configured with OSPF but is also being pre-configured 32 00:03:33,500 --> 00:03:40,910 with Network Address Translation. This lab is concentrating on subnetting so I pre-configured the NAT 33 00:03:41,030 --> 00:03:45,760 and routing protocols so that you didn't have to worry about that. 34 00:03:45,860 --> 00:03:47,660 Can we get to cisco.com? 35 00:03:47,810 --> 00:03:49,130 Yes, we can. 36 00:03:49,130 --> 00:03:51,040 Can we get to facebook 37 00:03:51,080 --> 00:03:54,020 .com? Yes, we can. 38 00:03:54,050 --> 00:03:56,610 So that works on PC 0. 39 00:03:56,630 --> 00:04:01,360 What about PC 2, can we get to cisco.com? 40 00:04:01,370 --> 00:04:02,750 Yes, we can. 41 00:04:02,750 --> 00:04:05,060 Can we get to facebook.com? 42 00:04:05,090 --> 00:04:06,810 Yes, we can. 43 00:04:06,810 --> 00:04:13,010 So I'm hoping you're ready at this point, you've learnt a lot about IP addressing, subnetting, how to configure 44 00:04:13,010 --> 00:04:17,990 it and how to make it practical in a network. In the next video 45 00:04:17,990 --> 00:04:24,170 I'm just going to continue doing something very similar for the other subnets and I'm going to speed 46 00:04:24,170 --> 00:04:27,020 it up by using tricks rather than binary.