WEBVTT 00:00.560 --> 00:05.060 When it comes to the networking, there is probably nothing that cannot be done with Linux. 00:05.090 --> 00:11.360 Linux is used to build all sorts of networking systems and appliances, including firewalls, routers, 00:11.390 --> 00:17.120 name servers, network attached storage nest boxes and on and on. 00:17.150 --> 00:19.740 So just the subject of networking is a farce. 00:19.760 --> 00:24.560 So are the number of commands that can be used to configure and control. 00:24.560 --> 00:31.070 It is so much closer than here, so we will focus our attention on just a few of the most frequently 00:31.070 --> 00:31.910 used ones. 00:31.910 --> 00:38.240 So the command chosen for examination include those used to monitor networks and those used to transfer 00:38.270 --> 00:38.620 files. 00:38.630 --> 00:41.120 In addition, we are going to explore the ssh. 00:41.190 --> 00:41.890 Ssh. 00:42.870 --> 00:43.490 Ssh. 00:44.320 --> 00:47.560 A program that is used to perform remote logins. 00:47.560 --> 00:56.190 And in this lecture you will also learn ping traceroute ftp w get ssh ftp netstat netstat. 00:56.230 --> 00:58.450 You will also learn traceroute. 00:59.200 --> 01:03.660 And you will also learn IP and etcetera networking commands. 01:03.670 --> 01:05.440 So let's get started. 01:05.530 --> 01:09.790 So let's actually firstly start with the mining and monitoring the networks. 01:09.790 --> 01:15.070 Even if you are not a system administrator, it's often helpful to examine the performance and operation 01:15.100 --> 01:16.000 of a network. 01:16.000 --> 01:18.640 So first let's start with the ping command here. 01:18.640 --> 01:21.850 So the most basic network command is a ping. 01:21.880 --> 01:27.640 The ping command sends a special network packet called actually, let me write it down. 01:27.640 --> 01:32.170 It's actually so long here, so we don't need that anymore. 01:32.170 --> 01:35.200 And here the ping command. 01:36.240 --> 01:39.270 Uh, sense a spatial network packet. 01:39.630 --> 01:40.440 Ping. 01:40.770 --> 01:41.640 Ping. 01:42.270 --> 01:45.210 Ping Command sends a ping. 01:45.210 --> 01:51.330 Command sends the spatial network packet named ICMP echo request. 01:52.050 --> 01:55.350 So, uh, this sets the two specified host. 01:55.350 --> 02:03.120 So most most networks devices receiving this packet will reply to it, allowing the network connection 02:03.120 --> 02:03.840 to be verified. 02:03.840 --> 02:09.900 And it's possible to configure most network devices, including Linux host to ignore these packets. 02:09.900 --> 02:15.420 And this is usually done for security reasons to partially obscure a host from a potential attacker. 02:15.420 --> 02:22.230 And it is also common for firewalls to be configured to block ICMP traffic, for example, to see whether 02:22.230 --> 02:24.910 we can reach to our telecom. 02:25.110 --> 02:33.750 Um, one of our favorite sites we can use ping command ping oxley.com and here actually it open at the 02:33.750 --> 02:38.190 browser to I want to show you how our website looks like here. 02:38.880 --> 02:41.910 And here, as you can see here, we are sending packets. 02:48.220 --> 02:54.070 And after that we will, uh, the Linux will show us the statistics of, of this pag pages here. 02:54.100 --> 02:55.600 oxley.com. 02:56.550 --> 02:58.620 And this is our website. 03:04.010 --> 03:04.890 Versus tuning. 03:04.910 --> 03:09.120 Digital forensics, Kotlin, cybersecurity and etcetera. 03:09.140 --> 03:11.870 And this is also our YouTube channel here. 03:14.340 --> 03:16.650 So let's look here. 03:16.650 --> 03:20.460 And as you can see, it still continues to sending pings here. 03:20.460 --> 03:27.210 So after now, we're going to interrupt with Control C and after when we interrupt it, we see the statistics 03:27.210 --> 03:32.100 here transmitted received packet loss and time, 51 seconds. 03:32.100 --> 03:34.830 And here we are seeing average minimum maximum. 03:34.860 --> 03:45.060 And so after it is interrupted in this case, after the 52 packet by pressing Ctrl C pink prints performance 03:45.060 --> 03:53.160 statistics, as you can see here and it properly performing network will exhibit the 0% packet loss. 03:53.160 --> 04:01.380 So in this case our packet is and web server host is good and a successful ping will indicate that the 04:01.380 --> 04:07.380 elements of the network, its interface cards, cabling, routing, the gateways are in a generally 04:07.380 --> 04:12.390 good working order and we also have the trace route. 04:12.390 --> 04:15.820 So the trace is route here. 04:15.820 --> 04:16.630 So. 04:18.120 --> 04:19.350 This trace route. 04:19.350 --> 04:21.000 Actually, let me see here. 04:21.000 --> 04:21.420 Yeah. 04:21.690 --> 04:28.950 Uh, though this trace route program and some systems use a similar to trace path program. 04:28.950 --> 04:32.310 And in this case we will the default is trace route is installed. 04:32.310 --> 04:34.260 So you don't need the trackpad for now. 04:35.020 --> 04:39.430 And the tracer program lists all the hops. 04:39.460 --> 04:43.630 Network traffic takes to get from the local server to a specified host. 04:43.660 --> 04:48.210 For example, to see the route taken to reach our telecom. 04:48.220 --> 04:58.780 You will do this trace route and trace route and here you will enter telecom trace route. 05:01.530 --> 05:04.770 And here we will see what it will take. 05:04.770 --> 05:09.480 So firstly, it's a local and then two, three, four, five, seven. 05:11.890 --> 05:16.150 Now after output, I will tell what it will show us here. 05:16.480 --> 05:22.510 And our our actual our web server has the firewall Cloudflare Firewall. 05:22.510 --> 05:27.970 And that's because maybe we will not get any results or any meaningful results here because. 05:29.620 --> 05:31.810 Our Web domain has a. 05:32.570 --> 05:35.840 However, and it's filtering the request here. 05:35.840 --> 05:37.880 And let's actually try Google.com. 06:03.060 --> 06:04.890 It's actually Try udemy.com. 06:15.450 --> 06:19.420 So that's how the traceroute program works. 06:19.440 --> 06:26.940 So in this output, we can see here the connecting from our test system to our udemy.com traversing 06:26.940 --> 06:27.810 16 routers. 06:27.810 --> 06:34.140 And actually we can also use the IPS for this um, here, 0.0.1. 06:34.140 --> 06:39.570 And here, as you can see here, it's just showing, showing us one, which is the localhost and it's 06:39.570 --> 06:40.680 our localhost here. 06:40.680 --> 06:41.460 So. 06:42.580 --> 06:48.070 Uh, we in cases where the routing information is blocked, we can sometimes overcome this by adding 06:48.070 --> 06:50.980 either the, uh, the adding either. 06:52.200 --> 06:58.590 Here actually adding either T or uppercase T or uppercase E command here. 06:58.590 --> 07:01.020 So operation is not you have privileges. 07:01.020 --> 07:04.440 So you will also use the pseudo for in order to use this. 07:04.440 --> 07:10.530 And as you can see here, we reached the telecom here and just in the two traces here. 07:10.530 --> 07:13.620 And actually let's try the E parameter here. 07:13.650 --> 07:16.710 E option here right now and here. 07:18.180 --> 07:19.460 Let's see what will happen. 07:19.470 --> 07:20.910 We are waiting for now. 07:21.660 --> 07:30.180 And here, as you can see here, we are reached in the ninth hop here and that is how our traceroute 07:30.180 --> 07:38.040 program and actually you can also use man traceroute to get more information about the traceroute program 07:38.040 --> 07:38.670 itself. 07:39.030 --> 07:46.020 Their description printer resource packet, restore networks and description parameters, options and 07:46.020 --> 07:46.740 etcetera. 07:46.740 --> 07:51.820 And let's go to our next tier which is IP command. 07:51.840 --> 08:00.030 So this IP program here, IP program is a multi-purpose network configuration tool that makes the use 08:00.030 --> 08:05.460 of the full range of networking features available in a modern Linux kernels. 08:05.460 --> 08:12.390 So it replaces the earlier and now it deprecated Ifconfig program with IP. 08:12.420 --> 08:17.280 We can examine systems, network interfaces and routing table. 08:17.280 --> 08:21.490 So in next lecture you will learn about the IP and netstat command. 08:21.490 --> 08:23.050 So I'm waiting you in next lecture.