1 00:00:00,890 --> 00:00:06,110 Now, before we configure our tunnels, we need to make sure that the tunnel endpoints have connectivity 2 00:00:06,110 --> 00:00:07,070 to each other. 3 00:00:07,070 --> 00:00:10,910 So router two should be able to ping, right a for and vice versa. 4 00:00:11,150 --> 00:00:15,680 In this example, I'm going to set up the tunnel from the serial interfaces. 5 00:00:15,800 --> 00:00:22,100 So logically it looks like we have this separate tunnel interface, but the tunnel is actually configured 6 00:00:22,100 --> 00:00:26,450 from serial 020 to serial 020. 7 00:00:27,110 --> 00:00:27,980 So rather two. 8 00:00:28,010 --> 00:00:31,700 Can we ping for to one to 2 to 2? 9 00:00:32,360 --> 00:00:33,530 Yes, we can. 10 00:00:34,070 --> 00:00:37,160 And en route of four, can we ping for one, two, one, two, one. 11 00:00:37,190 --> 00:00:38,180 Yes, we can. 12 00:00:38,780 --> 00:00:41,190 Now, ping uses a different protocol to go. 13 00:00:42,050 --> 00:00:49,220 So you need to confirm that you have connectivity using geo re from this interface to this interface. 14 00:00:49,550 --> 00:00:55,550 But for the moment, we've used Ping as our initial test to ensure that we have basic connectivity. 15 00:00:55,670 --> 00:01:01,970 So to configure a tunnel, you go to interface tunnel and you specify a number. 16 00:01:03,780 --> 00:01:06,470 I'm going to choose zero to keep it simple. 17 00:01:06,480 --> 00:01:10,230 But as you see, there's a wide range of tunnel numbers that you can choose from. 18 00:01:10,500 --> 00:01:13,050 Tunnel zero in this example has gone down. 19 00:01:13,440 --> 00:01:19,770 The tunnel interface will only come up if we have IP connectivity to the tunnel destination, which 20 00:01:19,770 --> 00:01:21,030 we still need to configure. 21 00:01:21,860 --> 00:01:29,330 But first, let's configure an IP address on the tunnel and I'm going to configure this as a slash 30 22 00:01:29,330 --> 00:01:30,260 network. 23 00:01:30,350 --> 00:01:34,160 And once again, we're going to use a private IP address. 24 00:01:34,550 --> 00:01:38,870 So we're going to be sending traffic across the Internet using private IP addresses. 25 00:01:38,870 --> 00:01:44,180 But it'll work because router three is going to route traffic based on the outer header. 26 00:01:45,380 --> 00:01:49,640 Or as described in the RFC is the delivery header. 27 00:01:50,550 --> 00:01:54,360 So the header and payload packet is not going to be read. 28 00:01:55,300 --> 00:02:02,080 By the Internet routers, they simply going to route traffic based on the delivery header. 29 00:02:03,040 --> 00:02:05,110 We need to specify the tunnel mode. 30 00:02:07,910 --> 00:02:11,810 Notice multiple options are available, but we're going to use JIRA. 31 00:02:12,570 --> 00:02:15,990 And IP version for that is actually the default. 32 00:02:15,990 --> 00:02:22,350 So when we look at the tunnel interface, you'll notice that command doesn't display because that is 33 00:02:22,350 --> 00:02:24,600 once again the default tunnel mode. 34 00:02:25,050 --> 00:02:27,450 We now need to specify the tunnel source. 35 00:02:28,200 --> 00:02:30,960 Notice the tunnel command gives you multiple options. 36 00:02:31,780 --> 00:02:36,520 We've already chosen mode, but now we'll select the source of the tunnel. 37 00:02:38,300 --> 00:02:41,530 You can choose a physical interface or an IP address. 38 00:02:41,540 --> 00:02:44,330 In this example, I'm simply going to choose IP address. 39 00:02:45,150 --> 00:02:53,670 And he'd enter the tunnel is going to originate from this IP address and it's going to go to a destination 40 00:02:54,120 --> 00:02:56,100 afforded 1 to 2.2. 41 00:02:56,790 --> 00:02:58,590 In other words, rather a four. 42 00:02:59,680 --> 00:03:06,760 As you can see, the tunnel has now come up and that's because we have IP connectivity from this router 43 00:03:06,760 --> 00:03:08,860 to the destination of the tunnel. 44 00:03:09,010 --> 00:03:13,120 The tunnel, however, is not going to work because we have to configure the other side. 45 00:03:13,420 --> 00:03:22,040 So kind of t interface tunnel zero on router four IP Address ten .1.3.2. 46 00:03:23,260 --> 00:03:24,880 Keep it in the same subnet. 47 00:03:26,000 --> 00:03:31,040 So this site is once again ten .1.3.1. 48 00:03:33,840 --> 00:03:35,880 And the side is 10.1. 49 00:03:36,220 --> 00:03:37,140 3.2. 50 00:03:39,150 --> 00:03:46,770 So back on route of four tunnel mode, geo IP, you don't have to specify that command because it's 51 00:03:46,770 --> 00:03:50,250 the default, but I'll do it here for completeness. 52 00:03:52,490 --> 00:03:53,360 Tunnel sources. 53 00:03:53,360 --> 00:03:54,980 4 to 1 or 2 to 2. 54 00:03:55,340 --> 00:03:57,140 Tunnel destination. 55 00:03:57,380 --> 00:03:59,150 It's four, two, one, two, one, two, one. 56 00:03:59,660 --> 00:04:08,840 And hopefully what we should see is that that tunnel comes up and there it does show IP interface brief 57 00:04:09,440 --> 00:04:14,090 shows us that we now have a tunnel interface that's up up on the side. 58 00:04:14,860 --> 00:04:16,570 And en route to. 59 00:04:19,160 --> 00:04:21,680 The tunnel is up on a two. 60 00:04:22,070 --> 00:04:24,590 So in order to, we should be able to ping, right. 61 00:04:24,590 --> 00:04:27,170 A force tunnel interface, which we can. 62 00:04:27,620 --> 00:04:35,870 So notice we pinging 10.1 or 3.2, but rather three has no visibility of that route. 63 00:04:39,020 --> 00:04:43,490 And that shows quite nicely that rather three is able to route traffic from this IP address to this 64 00:04:43,490 --> 00:04:47,420 IP address without actually reading those IP addresses. 65 00:04:47,570 --> 00:04:51,890 It's simply routing traffic based on the source to the destination. 66 00:04:53,050 --> 00:04:55,510 So let's prove that I'll start a CAPTCHA here. 67 00:04:56,190 --> 00:05:01,560 I'm going to start a CAPTCHA using LC because the default encapsulation is hdl-c. 68 00:05:02,220 --> 00:05:08,460 On Cisco serial links on interface serial 2/1 on router three. 69 00:05:13,790 --> 00:05:17,510 So at the moment we see CDP, we see some of the messages. 70 00:05:18,020 --> 00:05:23,420 But what I'll do is to a ping from router two to router four again. 71 00:05:25,240 --> 00:05:25,950 And there you go. 72 00:05:25,960 --> 00:05:27,670 There's our ICMP messages. 73 00:05:31,130 --> 00:05:34,400 So we can see it's an ICMP from ten to 1 to 3 to 1 to 10. 74 00:05:34,400 --> 00:05:35,840 To 1.3 to 2. 75 00:05:37,250 --> 00:05:39,470 The Layer two encapsulation is hdl-c. 76 00:05:39,500 --> 00:05:46,790 The protocol used at layer three is IP version four and notice the source and destination IP addresses 77 00:05:46,790 --> 00:05:50,630 4.1.1 and one destination is 4.12222. 78 00:05:51,080 --> 00:05:55,370 In other words, this router is sending traffic to this router. 79 00:05:56,120 --> 00:06:04,130 Rada three is going to root based on these IP addresses, not on the IP addresses contained in the encapsulated 80 00:06:04,130 --> 00:06:04,850 packet. 81 00:06:05,360 --> 00:06:11,720 At layer four, we can see that it's a generic routing encapsulation using IP version four. 82 00:06:12,680 --> 00:06:17,320 And inside there we can see the source tendered. 83 00:06:17,330 --> 00:06:18,410 One, two, three, two, one. 84 00:06:18,590 --> 00:06:21,380 And destination of ten .1.3.2. 85 00:06:21,590 --> 00:06:24,380 In other words, we've encapsulated. 86 00:06:25,630 --> 00:06:29,740 An IP version for packet within an IP version for packet. 87 00:06:30,650 --> 00:06:34,250 The original traffic was a ICMP ping. 88 00:06:34,610 --> 00:06:35,720 So there's the ping. 89 00:06:35,720 --> 00:06:42,950 And if we go to the next packet, we can see the ping reply encapsulated in IP version for within JURI, 90 00:06:42,980 --> 00:06:46,760 within IP version for within Hdl-c. 91 00:06:48,760 --> 00:06:52,710 So we've now successfully configured a tunnel from rather 2 to 2 out of four. 92 00:06:53,260 --> 00:06:54,580 I'll stop that capture. 93 00:06:55,830 --> 00:07:01,440 In the next video will check whether rudder one can ping root of five and do some more. 94 00:07:01,440 --> 00:07:04,680 Wireshark captures and do some other tests.