1 00:00:00,700 --> 00:00:07,120 You can once again look at RFC 2784 or go to the updated version 2890. 2 00:00:07,240 --> 00:00:13,150 To see some of the extra extensions to go back in to 784. 3 00:00:14,230 --> 00:00:21,340 Notice once again you can see the encapsulated packet with a payload header and delivery header. 4 00:00:21,640 --> 00:00:24,610 You can see what the grey header looks like. 5 00:00:25,000 --> 00:00:30,340 As an example, you can see the protocol type, you can see the version and other fields. 6 00:00:30,370 --> 00:00:34,180 That kind of information is explained in this RFC. 7 00:00:34,630 --> 00:00:40,510 But rather than boring you going through an RFC, I'm going to show you practically with a Wireshark 8 00:00:40,510 --> 00:00:43,900 capture what the actual packets look like. 9 00:00:44,650 --> 00:00:46,110 In our topology. 10 00:00:46,120 --> 00:00:48,070 So we'll capture some packets here. 11 00:00:48,850 --> 00:00:55,540 And we'll also capture them on the Internet to see how the packets are encapsulated and what headers 12 00:00:55,540 --> 00:00:56,230 are used. 13 00:00:57,180 --> 00:01:03,210 You can see the protocol type used by E in RFC 1700. 14 00:01:03,540 --> 00:01:08,580 And in this RFC, you'll see that Joey uses protocol number 47. 15 00:01:09,880 --> 00:01:14,740 Other protocols that you may be more familiar with include TCP, which is Protocol six. 16 00:01:16,100 --> 00:01:18,770 And UDP, which is Protocol 17. 17 00:01:21,150 --> 00:01:28,930 So the point to remember is GRC is a protocol that resides next to UDP and TCP. 18 00:01:29,070 --> 00:01:37,140 In the OSA model, GRC doesn't run on top of UDP or on top of TCP, it's its own protocol type. 19 00:01:37,410 --> 00:01:43,590 You can also see the ether type for Jerry in the Ethernet numbers on the IANA. 20 00:01:44,300 --> 00:01:49,790 But once again, I'm going to be using Wireshark to show you this, even though that kind of information 21 00:01:49,790 --> 00:01:52,040 is contained in the various RF keys. 22 00:01:52,880 --> 00:01:55,760 So let's get started configuring tunnels. 23 00:01:55,940 --> 00:02:04,070 In this example, rather, one and router five are configured as PCs topping the show IP Route Command. 24 00:02:04,100 --> 00:02:07,220 Shows me that no routing is enabled on this router. 25 00:02:07,610 --> 00:02:11,270 A default gateway has been configured to ten 112. 26 00:02:12,160 --> 00:02:18,190 Now I disabled routing on the router using the command. 27 00:02:18,190 --> 00:02:19,570 No IP routing. 28 00:02:19,750 --> 00:02:26,710 So this router doesn't even have a routing table as you would expect from a normal router. 29 00:02:27,100 --> 00:02:31,750 I've turned off routing and essentially turned the router into a PC. 30 00:02:33,380 --> 00:02:39,080 The router can ping its default gateway, which is reported to but cannot ping. 31 00:02:40,170 --> 00:02:41,400 Root of five. 32 00:02:43,500 --> 00:02:47,370 And that's because no routing has been configured on rather three. 33 00:02:50,200 --> 00:02:54,280 Rather three has only been configured with IP addresses. 34 00:02:54,880 --> 00:03:01,060 The command show IP route on router three shows us that it has directly connected interfaces. 35 00:03:01,600 --> 00:03:07,450 It has an interface here and an interface here, but no routing is configured. 36 00:03:07,600 --> 00:03:14,140 The only configuration at the moment is IP addresses on these interfaces, and the interfaces have been 37 00:03:14,140 --> 00:03:14,890 enabled. 38 00:03:15,280 --> 00:03:16,810 Once we've configured this topology. 39 00:03:16,840 --> 00:03:23,140 However, rather, one should be able to ping router five without router three having any visibility 40 00:03:23,290 --> 00:03:24,790 of the ten networks. 41 00:03:25,330 --> 00:03:27,950 Ten is once again in RFC 1918 address. 42 00:03:27,970 --> 00:03:30,070 In other words, it's a private IP address. 43 00:03:30,790 --> 00:03:35,470 I've used Network four, which is part of level three on the Internet. 44 00:03:35,470 --> 00:03:38,950 So this is a public IP address that belongs to an ISP. 45 00:03:39,100 --> 00:03:42,910 So I'm doing that in this topology to emulate the Internet. 46 00:03:43,360 --> 00:03:49,990 And once again, Router three in this example has no visibility of this network or this network, and 47 00:03:49,990 --> 00:03:55,450 we are not going to configure it with any visibility of these private IP addresses. 48 00:03:56,200 --> 00:04:03,130 But when the jury tunnel is configured logically, traffic is going to go across this Ethernet interface, 49 00:04:03,130 --> 00:04:05,800 hit this router, go through the tunnel. 50 00:04:06,500 --> 00:04:11,990 Come out of the tunnel and go across this Ethernet interface and hit four out of five and return back 51 00:04:11,990 --> 00:04:13,010 through the tunnel. 52 00:04:13,160 --> 00:04:16,339 So we should have connectivity between router one and router five. 53 00:04:17,480 --> 00:04:20,540 Now rather to and rather for have static default routes. 54 00:04:21,240 --> 00:04:22,590 Pointing to Rada three. 55 00:04:23,040 --> 00:04:29,640 So in this example, rather two is configured with an Internet facing IP address as well as an internal 56 00:04:29,640 --> 00:04:31,860 IP address on Fost Ethernet zero zero. 57 00:04:32,070 --> 00:04:37,170 And once again, with the default gateway pointing to router three, router four. 58 00:04:38,220 --> 00:04:39,360 Has something similar. 59 00:04:40,910 --> 00:04:46,670 Sure pirate shows default route pointing to ten 121, which is rather three. 60 00:04:48,120 --> 00:04:55,380 We have an Internet facing interface and an internal interface, but at the moment, no tunnels have 61 00:04:55,380 --> 00:04:57,210 been configured on these routers. 62 00:04:58,080 --> 00:05:06,120 So on router four, we see first Ethernet zero zero, we see Serial 2/0, but we don't see a tunnel 63 00:05:06,120 --> 00:05:09,270 interface and on router two. 64 00:05:10,690 --> 00:05:11,830 The same is true. 65 00:05:11,860 --> 00:05:13,900 There's Foster Ethernet zero zero. 66 00:05:15,240 --> 00:05:17,550 Here is serial 2/0. 67 00:05:17,970 --> 00:05:19,650 So that's the initial topology. 68 00:05:19,680 --> 00:05:25,920 Now let's configure the tunnel between router two and router four and prove that we can send traffic 69 00:05:25,920 --> 00:05:27,690 from router one to out of five.