WEBVTT 00:08.920 --> 00:14.640 Friends will come back in this lesson we we're going to learn about how to hold and who are in the clear. 00:14.700 --> 00:15.110 OK. 00:15.180 --> 00:19.150 Now Bruce listen we have to learn how to use the firewall. 00:19.170 --> 00:21.050 And so I was fine. 00:21.080 --> 00:21.590 OK. 00:21.800 --> 00:27.170 So listen we're going to learn more about Hoku harder the network here. 00:27.320 --> 00:27.760 OK. 00:28.070 --> 00:31.700 So let's see practically how to do this. 00:31.700 --> 00:34.810 OK I'll put up the file which is prison. 00:34.910 --> 00:37.560 It is a directory with sudo access. 00:37.810 --> 00:38.400 OK. 00:38.570 --> 00:40.920 So it is your. 00:40.990 --> 00:44.570 And live it's virus CNN.com. 00:45.170 --> 00:45.610 OK. 00:45.660 --> 00:49.420 And in this fight how and in the line of code. 00:49.600 --> 00:50.460 OK. 00:50.540 --> 00:53.930 Are obviously going to protect our server against different types of attack. 00:53.930 --> 00:54.530 OK. 00:54.770 --> 00:59.040 So let's talk about each core here and it's working. 00:59.060 --> 01:04.050 So the first block here you can see it's going to protect the server against spoofing attacks. 01:04.050 --> 01:11.420 OK then another of the protocols that were against IP spoofing attacks OK the last lesson we learned 01:11.450 --> 01:14.130 how to protect against spoofing. 01:14.210 --> 01:14.610 OK. 01:14.660 --> 01:19.630 So this is another way for protecting against IP spoofing attack. 01:20.030 --> 01:28.100 The next line is ignored ICMP block cost request means a hacker can always get some information. 01:28.250 --> 01:33.940 So VIGEN a block here the ping replied So keep this line going along the ping replies. 01:34.050 --> 01:39.070 OK so this line will protect against these kinds of attack. 01:39.140 --> 01:42.450 The next block is diciples source packet routing. 01:42.770 --> 01:50.270 So I would suspect that routing means it is a mechanism used by Internet protocol to get a packet from 01:50.370 --> 01:52.160 you so still destination. 01:52.490 --> 01:58.370 So what happens is a hacker kept in the back gate OK and he can get the information. 01:58.370 --> 02:05.390 The sensitive information like are led to the apology and by getting that possibly he can provide some 02:05.390 --> 02:06.910 damage to our system. 02:07.070 --> 02:15.720 OK so by adding these phone lines we can protect against these kinds of attacks hogi or Heiko Council 02:15.740 --> 02:17.990 bypass some security restriction. 02:18.040 --> 02:21.750 OK by getting to know this information OK. 02:22.190 --> 02:25.220 So the next block is ignore Sindhi. 02:25.280 --> 02:30.680 OK so ignoring the period that it's better for same reasons. 02:30.680 --> 02:38.810 The reason is that I said that basically is the part of the Cubists created by this the person rocking 02:38.820 --> 02:42.840 part of the network from the host choice. 02:42.860 --> 02:46.520 So what happens is hackers can easily get an opt in table. 02:46.520 --> 02:52.730 OK I'll take that out and he can send the traffic to his own choice so keep the incoming traffic to 02:52.730 --> 02:56.020 his own choice and in his fear he can damage it. 02:56.110 --> 03:01.430 We're in a different phase so we can block writing these lines. 03:01.480 --> 03:03.290 OK in this configuration. 03:03.290 --> 03:03.950 Fine. 03:04.170 --> 03:07.360 OK can the next Luckies thing attacks. 03:07.430 --> 03:11.540 Blocking does not work against syntax in similar attacks. 03:11.540 --> 03:18.390 What happens is an attacker since hundreds of thousands of messages to the server. 03:18.500 --> 03:21.890 So do do that what happens is our them gets full. 03:21.920 --> 03:28.030 OK so this software could get hang or get slower. 03:28.080 --> 03:32.760 So OK so that our performance is kicked down. 03:32.790 --> 03:41.060 OK so performance get down to this attack so we can easily block these kinds of Courtown Ed in these 03:41.100 --> 03:43.060 four lines of code here. 03:43.330 --> 03:49.310 OK the next block is logged my audience in lock Martyn's what happens. 03:49.400 --> 03:52.880 And attack could send the packets from fake IP. 03:53.030 --> 04:00.350 Or you can call it as the IP which is not present to Kamins the same IP addresses is reserved for experimental 04:00.350 --> 04:00.870 purposes. 04:00.890 --> 04:07.600 So in these types of contacts what happens is our server by the time it is used to by our server to 04:07.650 --> 04:14.900 process that packet and our silver band we get hysterical in an article since these kinds of packet 04:14.960 --> 04:22.940 are daemon burned with the gate just so we can easily block log my inspired software by adding these 04:22.940 --> 04:24.210 two lines of code. 04:24.710 --> 04:30.460 And the last one is ignoring data pings by using some software. 04:30.740 --> 04:38.600 Heckert can send hundreds of thousands of requests from different parts of the world from different 04:38.600 --> 04:39.440 computers. 04:39.490 --> 04:48.360 So we're OK and these things are caused by tick tick pings and that so were get down or get crushed. 04:48.450 --> 04:53.050 OK so we can protect those that were against the data attack. 04:53.240 --> 05:00.870 OK so in this way we can Hudner were not clear OK from all these kinds of possible attacks.