1 00:00:00,700 --> 00:00:09,040 So at the moment in this topology router two is running Nat on fast Ethernet zero one and is doing overloading 2 00:00:09,040 --> 00:00:12,640 on that interface to allow router one and router four. 3 00:00:13,490 --> 00:00:15,380 To connect to router three. 4 00:00:15,950 --> 00:00:19,320 So ping eight at 1.1 to 2. 5 00:00:21,110 --> 00:00:25,220 Rather one is now able to connect to router three. 6 00:00:26,720 --> 00:00:26,870 Now. 7 00:00:26,870 --> 00:00:28,050 This is only for fun. 8 00:00:28,070 --> 00:00:30,920 What I'm going to do now is extend the topology. 9 00:00:31,670 --> 00:00:37,460 And connect three to my physical network interface card. 10 00:00:37,970 --> 00:00:40,820 So I'm going to connect it to my local area network. 11 00:00:41,510 --> 00:00:45,950 And what I'll do is add another Ethernet interface. 12 00:00:46,990 --> 00:00:55,900 To route a t so rather to is now connected to the outside world on first Ethernet 1/0. 13 00:00:57,280 --> 00:01:07,360 So on router two, interface 1/0, no shut IP address dhcp so that I get an IP address via DHCP. 14 00:01:09,030 --> 00:01:16,170 This interface connects me to my local area network, which in turn connects me to the internet so I 15 00:01:16,170 --> 00:01:17,550 can ping the internet. 16 00:01:18,740 --> 00:01:28,640 From my Windows PC as an example, and I've now bridged gaps three to the same network. 17 00:01:29,000 --> 00:01:34,010 The router has been allocated to this address and this is another reason to use overloading. 18 00:01:35,260 --> 00:01:40,960 To an interface because previously we configured an IP address statically. 19 00:01:41,260 --> 00:01:45,880 But on this new interface, we don't have an IP address statically configured. 20 00:01:46,120 --> 00:01:48,850 The IP address is dynamically configured. 21 00:01:49,920 --> 00:01:51,810 So you want to overload the interface. 22 00:01:51,810 --> 00:01:59,370 So IP net inside source list specify an access list, one which we created previously. 23 00:02:00,090 --> 00:02:05,100 In this case, I'm going to overload first ethernet 1/0. 24 00:02:06,760 --> 00:02:09,130 To allow both hosts to be netted. 25 00:02:10,270 --> 00:02:12,760 And to be able to connect to the internet. 26 00:02:12,820 --> 00:02:20,260 So show IP net translations shows no translations at the moment, but I've enabled net on this interface 27 00:02:20,260 --> 00:02:21,820 as well as this interface. 28 00:02:22,210 --> 00:02:24,070 So rather one ping. 29 00:02:24,730 --> 00:02:27,430 Google dot com. 30 00:02:29,130 --> 00:02:30,050 It doesn't work. 31 00:02:30,060 --> 00:02:33,210 I need to enable IP domain lookup. 32 00:02:34,750 --> 00:02:36,970 And I need to specify a name server. 33 00:02:39,110 --> 00:02:41,120 And in this example I'll just use google. 34 00:02:42,050 --> 00:02:46,100 So ping google.com show up in net translations. 35 00:02:46,100 --> 00:02:48,290 I'm not seeing any translations at the moment. 36 00:02:50,870 --> 00:02:52,310 So let's do some troubleshooting. 37 00:02:52,340 --> 00:02:53,690 Show IP route. 38 00:02:54,540 --> 00:03:01,320 We have a default route to ten 112 ping ten 112. 39 00:03:01,350 --> 00:03:02,670 We can ping the Ryder. 40 00:03:03,350 --> 00:03:06,860 So let's do a debug IP nat on this router. 41 00:03:09,330 --> 00:03:15,540 I'll also check whether this router can ping google.com directly the moment it can. 42 00:03:15,540 --> 00:03:15,850 So. 43 00:03:15,870 --> 00:03:18,330 IP domain lookup. 44 00:03:18,870 --> 00:03:20,250 IP name. 45 00:03:20,250 --> 00:03:21,000 Server. 46 00:03:22,620 --> 00:03:23,880 Specify Google. 47 00:03:26,240 --> 00:03:28,490 So that dorada camping google. 48 00:03:30,090 --> 00:03:32,010 Get the local router to ping Google. 49 00:03:34,230 --> 00:03:36,210 Let's see if we. 50 00:03:37,260 --> 00:03:38,400 See a problem. 51 00:03:39,940 --> 00:03:42,510 If zero zero is on the inside. 52 00:03:42,520 --> 00:03:43,450 That's right. 53 00:03:45,590 --> 00:03:48,140 If zero one is on the outside. 54 00:03:49,130 --> 00:03:50,240 That's correct. 55 00:03:50,570 --> 00:03:57,470 But I forgot to put IP Nat outside on fost ethernet one zero. 56 00:03:57,740 --> 00:04:04,670 So IP Nat outside needs to be enabled on that interface show IP net. 57 00:04:06,700 --> 00:04:07,840 Translations. 58 00:04:07,900 --> 00:04:09,240 No translations at the moment. 59 00:04:09,250 --> 00:04:10,660 Let's ping google.com. 60 00:04:11,580 --> 00:04:13,710 That looks a lot better ping succeed. 61 00:04:14,750 --> 00:04:17,000 And I'm getting my natural translation. 62 00:04:17,000 --> 00:04:23,930 So 10.1 and 1.1 that rather is translated to 1921681 159. 63 00:04:24,260 --> 00:04:25,490 Going to Google. 64 00:04:26,210 --> 00:04:32,870 At the top here, you can see the dense query to the Google DNS servers and then a reply comes back. 65 00:04:33,050 --> 00:04:40,550 So this router running in Genius three is doing DNS queries against Google's DNS server on the Internet. 66 00:04:41,000 --> 00:04:45,700 Locally, the route has been netted from ten 111 to this address. 67 00:04:45,710 --> 00:04:51,320 Now that is a another RFC 1918 address, but on router two. 68 00:04:53,190 --> 00:05:03,210 Through DHCP, Morata has learned that the default gateway is 1921681254, which is my local DSL Internet 69 00:05:03,210 --> 00:05:03,870 router. 70 00:05:04,350 --> 00:05:06,780 You can see some of the net queries timing out here. 71 00:05:07,080 --> 00:05:08,370 Let's do a ping again. 72 00:05:09,590 --> 00:05:10,850 Show IP. 73 00:05:10,910 --> 00:05:12,380 Net translation. 74 00:05:13,590 --> 00:05:15,960 There's a net translation in the table. 75 00:05:16,530 --> 00:05:19,140 I could, as an example, telnet. 76 00:05:20,210 --> 00:05:23,030 To Google.com on port 80. 77 00:05:24,650 --> 00:05:27,020 It's connected, so the connection is open. 78 00:05:27,320 --> 00:05:31,790 You can see that the traffic is being netted there. 79 00:05:31,790 --> 00:05:32,930 It's going out. 80 00:05:33,800 --> 00:05:34,730 I'll press control. 81 00:05:34,730 --> 00:05:38,690 See here, you can see we get some bad HTML. 82 00:05:39,420 --> 00:05:42,300 And the net continues. 83 00:05:42,930 --> 00:05:45,090 I could, as an example, go to another website. 84 00:05:45,090 --> 00:05:46,830 Let's go to Yahoo.com. 85 00:05:47,670 --> 00:05:50,370 So they address is 46. 86 00:05:52,050 --> 00:05:53,790 I forgot to put the port number in. 87 00:05:54,090 --> 00:05:56,070 So the net is taking place. 88 00:05:56,840 --> 00:05:58,870 But the server denied the connection. 89 00:05:58,880 --> 00:06:06,590 Let's go to Port 80 and you can see that the connection is now opened to Yahoo.com and we can see the 90 00:06:06,590 --> 00:06:08,570 net translations taking place. 91 00:06:09,200 --> 00:06:09,800 Press control. 92 00:06:09,830 --> 00:06:10,400 See? 93 00:06:12,040 --> 00:06:17,740 We get a bunch of HTML here and you can see some translations taking place. 94 00:06:18,170 --> 00:06:21,130 Notice here's the body of the HTML. 95 00:06:22,100 --> 00:06:24,770 And if we scroll up, we'll probably be able to see. 96 00:06:26,780 --> 00:06:30,320 Some messages from Yahoo.com as an example. 97 00:06:30,590 --> 00:06:37,220 So that's an example of using overloading on two separate interfaces. 98 00:06:37,250 --> 00:06:40,550 In one example, we're keeping it within three. 99 00:06:40,790 --> 00:06:44,030 And then the other example, we actually connecting to the Internet.