1 00:00:00,560 --> 00:00:05,060 When it comes to the networking, there is probably nothing that cannot be done with Linux. 2 00:00:05,090 --> 00:00:11,360 Linux is used to build all sorts of networking systems and appliances, including firewalls, routers, 3 00:00:11,390 --> 00:00:17,120 name servers, network attached storage nest boxes and on and on. 4 00:00:17,150 --> 00:00:19,740 So just the subject of networking is a farce. 5 00:00:19,760 --> 00:00:24,560 So are the number of commands that can be used to configure and control. 6 00:00:24,560 --> 00:00:31,070 It is so much closer than here, so we will focus our attention on just a few of the most frequently 7 00:00:31,070 --> 00:00:31,910 used ones. 8 00:00:31,910 --> 00:00:38,240 So the command chosen for examination include those used to monitor networks and those used to transfer 9 00:00:38,270 --> 00:00:38,620 files. 10 00:00:38,630 --> 00:00:41,120 In addition, we are going to explore the ssh. 11 00:00:41,190 --> 00:00:41,890 Ssh. 12 00:00:42,870 --> 00:00:43,490 Ssh. 13 00:00:44,320 --> 00:00:47,560 A program that is used to perform remote logins. 14 00:00:47,560 --> 00:00:56,190 And in this lecture you will also learn ping traceroute ftp w get ssh ftp netstat netstat. 15 00:00:56,230 --> 00:00:58,450 You will also learn traceroute. 16 00:00:59,200 --> 00:01:03,660 And you will also learn IP and etcetera networking commands. 17 00:01:03,670 --> 00:01:05,440 So let's get started. 18 00:01:05,530 --> 00:01:09,790 So let's actually firstly start with the mining and monitoring the networks. 19 00:01:09,790 --> 00:01:15,070 Even if you are not a system administrator, it's often helpful to examine the performance and operation 20 00:01:15,100 --> 00:01:16,000 of a network. 21 00:01:16,000 --> 00:01:18,640 So first let's start with the ping command here. 22 00:01:18,640 --> 00:01:21,850 So the most basic network command is a ping. 23 00:01:21,880 --> 00:01:27,640 The ping command sends a special network packet called actually, let me write it down. 24 00:01:27,640 --> 00:01:32,170 It's actually so long here, so we don't need that anymore. 25 00:01:32,170 --> 00:01:35,200 And here the ping command. 26 00:01:36,240 --> 00:01:39,270 Uh, sense a spatial network packet. 27 00:01:39,630 --> 00:01:40,440 Ping. 28 00:01:40,770 --> 00:01:41,640 Ping. 29 00:01:42,270 --> 00:01:45,210 Ping Command sends a ping. 30 00:01:45,210 --> 00:01:51,330 Command sends the spatial network packet named ICMP echo request. 31 00:01:52,050 --> 00:01:55,350 So, uh, this sets the two specified host. 32 00:01:55,350 --> 00:02:03,120 So most most networks devices receiving this packet will reply to it, allowing the network connection 33 00:02:03,120 --> 00:02:03,840 to be verified. 34 00:02:03,840 --> 00:02:09,900 And it's possible to configure most network devices, including Linux host to ignore these packets. 35 00:02:09,900 --> 00:02:15,420 And this is usually done for security reasons to partially obscure a host from a potential attacker. 36 00:02:15,420 --> 00:02:22,230 And it is also common for firewalls to be configured to block ICMP traffic, for example, to see whether 37 00:02:22,230 --> 00:02:24,910 we can reach to our telecom. 38 00:02:25,110 --> 00:02:33,750 Um, one of our favorite sites we can use ping command ping oxley.com and here actually it open at the 39 00:02:33,750 --> 00:02:38,190 browser to I want to show you how our website looks like here. 40 00:02:38,880 --> 00:02:41,910 And here, as you can see here, we are sending packets. 41 00:02:48,220 --> 00:02:54,070 And after that we will, uh, the Linux will show us the statistics of, of this pag pages here. 42 00:02:54,100 --> 00:02:55,600 oxley.com. 43 00:02:56,550 --> 00:02:58,620 And this is our website. 44 00:03:04,010 --> 00:03:04,890 Versus tuning. 45 00:03:04,910 --> 00:03:09,120 Digital forensics, Kotlin, cybersecurity and etcetera. 46 00:03:09,140 --> 00:03:11,870 And this is also our YouTube channel here. 47 00:03:14,340 --> 00:03:16,650 So let's look here. 48 00:03:16,650 --> 00:03:20,460 And as you can see, it still continues to sending pings here. 49 00:03:20,460 --> 00:03:27,210 So after now, we're going to interrupt with Control C and after when we interrupt it, we see the statistics 50 00:03:27,210 --> 00:03:32,100 here transmitted received packet loss and time, 51 seconds. 51 00:03:32,100 --> 00:03:34,830 And here we are seeing average minimum maximum. 52 00:03:34,860 --> 00:03:45,060 And so after it is interrupted in this case, after the 52 packet by pressing Ctrl C pink prints performance 53 00:03:45,060 --> 00:03:53,160 statistics, as you can see here and it properly performing network will exhibit the 0% packet loss. 54 00:03:53,160 --> 00:04:01,380 So in this case our packet is and web server host is good and a successful ping will indicate that the 55 00:04:01,380 --> 00:04:07,380 elements of the network, its interface cards, cabling, routing, the gateways are in a generally 56 00:04:07,380 --> 00:04:12,390 good working order and we also have the trace route. 57 00:04:12,390 --> 00:04:15,820 So the trace is route here. 58 00:04:15,820 --> 00:04:16,630 So. 59 00:04:18,120 --> 00:04:19,350 This trace route. 60 00:04:19,350 --> 00:04:21,000 Actually, let me see here. 61 00:04:21,000 --> 00:04:21,420 Yeah. 62 00:04:21,690 --> 00:04:28,950 Uh, though this trace route program and some systems use a similar to trace path program. 63 00:04:28,950 --> 00:04:32,310 And in this case we will the default is trace route is installed. 64 00:04:32,310 --> 00:04:34,260 So you don't need the trackpad for now. 65 00:04:35,020 --> 00:04:39,430 And the tracer program lists all the hops. 66 00:04:39,460 --> 00:04:43,630 Network traffic takes to get from the local server to a specified host. 67 00:04:43,660 --> 00:04:48,210 For example, to see the route taken to reach our telecom. 68 00:04:48,220 --> 00:04:58,780 You will do this trace route and trace route and here you will enter telecom trace route. 69 00:05:01,530 --> 00:05:04,770 And here we will see what it will take. 70 00:05:04,770 --> 00:05:09,480 So firstly, it's a local and then two, three, four, five, seven. 71 00:05:11,890 --> 00:05:16,150 Now after output, I will tell what it will show us here. 72 00:05:16,480 --> 00:05:22,510 And our our actual our web server has the firewall Cloudflare Firewall. 73 00:05:22,510 --> 00:05:27,970 And that's because maybe we will not get any results or any meaningful results here because. 74 00:05:29,620 --> 00:05:31,810 Our Web domain has a. 75 00:05:32,570 --> 00:05:35,840 However, and it's filtering the request here. 76 00:05:35,840 --> 00:05:37,880 And let's actually try Google.com. 77 00:06:03,060 --> 00:06:04,890 It's actually Try udemy.com. 78 00:06:15,450 --> 00:06:19,420 So that's how the traceroute program works. 79 00:06:19,440 --> 00:06:26,940 So in this output, we can see here the connecting from our test system to our udemy.com traversing 80 00:06:26,940 --> 00:06:27,810 16 routers. 81 00:06:27,810 --> 00:06:34,140 And actually we can also use the IPS for this um, here, 0.0.1. 82 00:06:34,140 --> 00:06:39,570 And here, as you can see here, it's just showing, showing us one, which is the localhost and it's 83 00:06:39,570 --> 00:06:40,680 our localhost here. 84 00:06:40,680 --> 00:06:41,460 So. 85 00:06:42,580 --> 00:06:48,070 Uh, we in cases where the routing information is blocked, we can sometimes overcome this by adding 86 00:06:48,070 --> 00:06:50,980 either the, uh, the adding either. 87 00:06:52,200 --> 00:06:58,590 Here actually adding either T or uppercase T or uppercase E command here. 88 00:06:58,590 --> 00:07:01,020 So operation is not you have privileges. 89 00:07:01,020 --> 00:07:04,440 So you will also use the pseudo for in order to use this. 90 00:07:04,440 --> 00:07:10,530 And as you can see here, we reached the telecom here and just in the two traces here. 91 00:07:10,530 --> 00:07:13,620 And actually let's try the E parameter here. 92 00:07:13,650 --> 00:07:16,710 E option here right now and here. 93 00:07:18,180 --> 00:07:19,460 Let's see what will happen. 94 00:07:19,470 --> 00:07:20,910 We are waiting for now. 95 00:07:21,660 --> 00:07:30,180 And here, as you can see here, we are reached in the ninth hop here and that is how our traceroute 96 00:07:30,180 --> 00:07:38,040 program and actually you can also use man traceroute to get more information about the traceroute program 97 00:07:38,040 --> 00:07:38,670 itself. 98 00:07:39,030 --> 00:07:46,020 Their description printer resource packet, restore networks and description parameters, options and 99 00:07:46,020 --> 00:07:46,740 etcetera. 100 00:07:46,740 --> 00:07:51,820 And let's go to our next tier which is IP command. 101 00:07:51,840 --> 00:08:00,030 So this IP program here, IP program is a multi-purpose network configuration tool that makes the use 102 00:08:00,030 --> 00:08:05,460 of the full range of networking features available in a modern Linux kernels. 103 00:08:05,460 --> 00:08:12,390 So it replaces the earlier and now it deprecated Ifconfig program with IP. 104 00:08:12,420 --> 00:08:17,280 We can examine systems, network interfaces and routing table. 105 00:08:17,280 --> 00:08:21,490 So in next lecture you will learn about the IP and netstat command. 106 00:08:21,490 --> 00:08:23,050 So I'm waiting you in next lecture.