1 00:00:02,090 --> 00:00:03,670 So let's talk about this. 2 00:00:03,690 --> 00:00:09,770 I was actually this is the redneck's comment I should cover in the next essential section, but we need 3 00:00:09,770 --> 00:00:11,630 to understand how the world works. 4 00:00:11,840 --> 00:00:17,330 So that's why I think this section would be good to introduce you to the evidence. 5 00:00:17,600 --> 00:00:19,630 So we have seen the Windows firewall. 6 00:00:19,910 --> 00:00:23,350 We have seen the program for paneling and broken connections. 7 00:00:23,930 --> 00:00:27,070 That is the same purpose you can do with the IP Dabbous. 8 00:00:27,440 --> 00:00:32,780 But we have to follow some options because it's a command line. 9 00:00:33,800 --> 00:00:43,280 So if you tell tables, it's just coming out front because it's in it's been pointed out that is where 10 00:00:43,730 --> 00:00:49,500 you need to get these IP tables as a route to the future. 11 00:00:49,520 --> 00:00:56,450 My but there was one in which we need the, uh, password and you get a bunch of options here. 12 00:00:58,590 --> 00:01:10,770 So first, I would explain some theory, so to see what are the IP tables that are used in your computer 13 00:01:10,930 --> 00:01:14,030 to minus a minus in the stands for. 14 00:01:15,120 --> 00:01:21,810 And you can see here there are three chains by default in pushing forward and output chip. 15 00:01:22,230 --> 00:01:26,370 So if you have to put any rule, you get in here. 16 00:01:28,080 --> 00:01:32,860 So the input is similar to in in bundles in the underside. 17 00:01:33,240 --> 00:01:40,750 So whatever connections that are coming from outside Internet to this computer will be added here. 18 00:01:41,670 --> 00:01:49,740 So the output chain consists of the connections going from our computer to the external website or any 19 00:01:49,740 --> 00:01:50,460 other computers. 20 00:01:50,460 --> 00:01:56,240 And that chain will be added here that it is similar to the opener's. 21 00:01:56,550 --> 00:02:02,600 So this forward is usually the rotors to forward the packet. 22 00:02:03,060 --> 00:02:10,690 So it will not be seen for that much because it will be using the rotors and for simple computer system. 23 00:02:10,710 --> 00:02:12,000 It is not necessary. 24 00:02:13,620 --> 00:02:23,250 So here you can see in the input input that the default one is xcept so we can browse the Internet and 25 00:02:23,250 --> 00:02:24,260 we can get the data. 26 00:02:25,230 --> 00:02:28,800 I can see the target protocol option, source destination. 27 00:02:29,160 --> 00:02:38,960 So in order to understand this, let me write a simple word for this IP input chain, Soula. 28 00:02:40,830 --> 00:02:49,320 So to add a to specific capitally infrared or appart so to which you need to happen to inputting. 29 00:02:49,650 --> 00:03:00,240 So incoming connections, I want to filter incoming connections and the same minus gear, minus days 30 00:03:00,240 --> 00:03:01,210 for action. 31 00:03:01,710 --> 00:03:09,920 So if you have you can see the actions you need to o you can perform acts of ridicule. 32 00:03:10,350 --> 00:03:11,470 So let's drop. 33 00:03:11,840 --> 00:03:20,870 So this drop simply, uh, discards the packet that are coming to our computer because this is the inputting. 34 00:03:21,270 --> 00:03:21,640 Right. 35 00:03:22,200 --> 00:03:31,920 So if I hit enter now, our rule is that if I say I put was minus cell, you can see uh, there is a 36 00:03:31,920 --> 00:03:36,840 rule at and it says target drop and protocol, our protocols. 37 00:03:36,840 --> 00:03:46,050 So whatever, uh, the sources and whatever their destination or piece, I mean destination, uh interfaces, 38 00:03:46,290 --> 00:03:52,530 uh, computer can have more than one interfaces and to whatever destination and all the protocols will 39 00:03:52,530 --> 00:03:54,110 simply drop the connection. 40 00:03:56,880 --> 00:04:02,790 Let me open a Web browser and let's pipe a good outcome. 41 00:04:17,420 --> 00:04:26,070 So this Web browser keeps rolling in for a treat because we will we can send our open request to the 42 00:04:26,070 --> 00:04:31,640 Web server, but the Google dot com has sent a response. 43 00:04:31,820 --> 00:04:39,470 But the response has been dropped because of this IP, uh, IPTV. 44 00:04:40,130 --> 00:04:44,090 So we are dropping from any source to any destination IP address. 45 00:04:44,090 --> 00:04:46,640 That is our mission and we are just dropping. 46 00:04:48,770 --> 00:04:54,230 So now what we can do is I'm going to delete this rule. 47 00:04:56,360 --> 00:05:02,280 So to do that, let's we need to find a number of these, uh. 48 00:05:08,150 --> 00:05:14,690 We need to sell minus sell, and we need to set the numbers. 49 00:05:16,650 --> 00:05:17,860 So numbers. 50 00:05:22,360 --> 00:05:28,540 As you can see, this is the first rule and the number is one, so using this right number, you can 51 00:05:28,550 --> 00:05:36,130 delete the, uh, I repeat tables and let's, uh, uh, my cap. 52 00:05:36,130 --> 00:05:38,680 Thirty four digit and one. 53 00:05:41,960 --> 00:05:47,330 So I think we need to somebody does something like this in the. 54 00:05:55,560 --> 00:06:02,460 OK, let's delete everything to do that, we need to see if we have stands for fresh, we need to flesh 55 00:06:02,460 --> 00:06:03,110 out the rules. 56 00:06:03,750 --> 00:06:10,520 So if I say minus capital, we we no longer have the rule in our input. 57 00:06:11,070 --> 00:06:15,280 Now, if I go to the browser and if I refer this, we can see guru.com. 58 00:06:17,520 --> 00:06:21,150 This is how you add the input chain. 59 00:06:23,890 --> 00:06:32,890 So there is some more syntax, some more options, you can specify I was minus here happen to the input 60 00:06:32,890 --> 00:06:38,080 chain, I mean, incoming connections and you can also specify the source using mitosis. 61 00:06:38,590 --> 00:06:41,280 So you need to type the IP address. 62 00:06:41,530 --> 00:06:44,620 But first, let me show you Google dot com. 63 00:06:45,730 --> 00:06:53,470 So connections from the source, Google dot com and I can specify the destination, but using minus 64 00:06:53,470 --> 00:06:58,670 one spot and 80 so I can sell minus drop. 65 00:07:00,040 --> 00:07:10,450 So as you can see, uh, if I'm getting any connections from this Google dot com and on the put it through 66 00:07:10,450 --> 00:07:16,570 before defining the what you need to specify the protocol, which is TCP UDP are any other protocol. 67 00:07:21,200 --> 00:07:25,420 Since it wouldn't be the typical protocol, notices would disappear. 68 00:07:27,260 --> 00:07:28,940 So let me explain this one. 69 00:07:29,180 --> 00:07:36,920 So I'm adding a rule to incoming connections rather than incoming corrections are from Google dot com 70 00:07:36,920 --> 00:07:37,370 source. 71 00:07:37,520 --> 00:07:44,420 And the full protocol is PXP with the destination, potentially destination port in the sense of which 72 00:07:45,050 --> 00:07:45,710 it is our. 73 00:07:46,070 --> 00:07:52,460 So Google accounts server sense that the destination would be 30 and what they want to take the action 74 00:07:52,460 --> 00:07:53,070 is drop. 75 00:07:53,690 --> 00:07:56,770 And if I were to my room will be successfully. 76 00:07:56,870 --> 00:07:58,150 Now, I can simply say. 77 00:08:01,940 --> 00:08:06,530 So as you can see here, Rob, PXP options, there are no extra options. 78 00:08:06,730 --> 00:08:07,730 You can see the source. 79 00:08:07,910 --> 00:08:11,330 It is a name, Sagrera of the Guru.com. 80 00:08:11,510 --> 00:08:20,670 So Boulder contains more than one name server, and we get the response from the other animals as well. 81 00:08:20,900 --> 00:08:24,610 If I flip the switch, we can see guru.com. 82 00:08:25,970 --> 00:08:36,380 Know, what I'm going to do is I'm going to, uh, being that being the Google dot com. 83 00:08:40,830 --> 00:08:42,400 So this is the IP address. 84 00:08:43,050 --> 00:08:48,990 Now, what I want to do is I am going to add the IP address instead of the domain name. 85 00:08:51,240 --> 00:08:52,920 So let me say this one. 86 00:08:57,040 --> 00:09:05,590 Now, if I go to the president, if I could enter, so you've still got this, maybe, uh, the our 87 00:09:05,590 --> 00:09:08,680 computer is asking for mininum servers. 88 00:09:09,590 --> 00:09:11,070 So let me go to this. 89 00:09:12,310 --> 00:09:13,260 So this is my card. 90 00:09:13,270 --> 00:09:18,100 You said, well, this is not easy to deal with, me being this one. 91 00:09:25,960 --> 00:09:32,050 All right, now let me copy paste this IP address and this chain. 92 00:09:37,130 --> 00:09:41,910 So now let me go ahead and navigate to this one. 93 00:09:41,930 --> 00:09:43,400 So let me rephrase this. 94 00:09:49,900 --> 00:09:52,510 All right, maybe test Poonam Sarver's. 95 00:09:58,280 --> 00:09:58,660 OK. 96 00:09:59,630 --> 00:10:02,510 I don't know why it's still we are getting. 97 00:10:08,870 --> 00:10:16,190 All right, maybe I have done wrong, but it's the same syntax you need to specify the source and the 98 00:10:16,190 --> 00:10:19,340 port and the destination port minus the drop. 99 00:10:19,910 --> 00:10:21,920 So let me read this. 100 00:10:26,120 --> 00:10:27,080 It would retard. 101 00:10:32,340 --> 00:10:42,660 Now, another thing we need to do is that is the output chain, should I tables, uh, upon the output? 102 00:10:44,730 --> 00:10:52,420 So now we if we want to connect to any Web server, then we cannot connect to it. 103 00:10:52,560 --> 00:10:55,580 So similar minus a source. 104 00:10:56,670 --> 00:11:05,950 This my IP address and the fourth protocol, TCP and Destination Port. 105 00:11:06,840 --> 00:11:12,180 OK, we'll, uh, drop out of the packets on all the ports and let's drop. 106 00:11:15,120 --> 00:11:25,680 So now if we connect to this Web server on the TCP IP protocol on any port, our packet will be dropped. 107 00:11:26,670 --> 00:11:28,320 Now, I think we should not get the. 108 00:11:30,310 --> 00:11:30,700 OK. 109 00:11:34,450 --> 00:11:37,360 Too bad at writing these rules. 110 00:12:00,980 --> 00:12:05,240 Let me try to, uh, specify the interface. 111 00:12:09,490 --> 00:12:15,270 So I'm just I don't know why it's I'm still able to pinging. 112 00:12:22,090 --> 00:12:22,960 So. 113 00:12:30,650 --> 00:12:38,540 So that's about this input output and for a change of fashion, we do not get the response rate, but 114 00:12:38,540 --> 00:12:41,310 later on, I don't know what you are getting the response. 115 00:12:41,810 --> 00:12:47,540 OK, so even maybe I am better writing the rules. 116 00:12:47,850 --> 00:12:57,560 OK, another thing I want to show you is not Abels pseudo IP tables, so you need to respond minus T 117 00:12:58,010 --> 00:12:59,090 and Fernet. 118 00:13:00,020 --> 00:13:01,610 There is a table for that. 119 00:13:02,240 --> 00:13:07,220 And we to say uh minus A. 120 00:13:10,290 --> 00:13:15,810 So, OK, I want to show you this one night stands for our network address translation. 121 00:13:15,990 --> 00:13:23,520 So we have already discussed this and the networking fundamentals, and this is used primarily for saving 122 00:13:23,520 --> 00:13:31,220 the public IP addresses, as you can see how the treatment preloading input output. 123 00:13:31,240 --> 00:13:33,060 We already know input and output. 124 00:13:35,650 --> 00:13:45,600 So what we can do is we can all of this back in, coming back to another port or to another IP address 125 00:13:45,610 --> 00:13:46,010 and the port. 126 00:13:47,650 --> 00:13:56,680 So if any computer is sending any data on the ports vital, there are a range of ports from 5000 to 127 00:13:56,680 --> 00:13:57,310 6000. 128 00:13:57,550 --> 00:14:02,660 No, I can drop those data into some one common Port Said 2000. 129 00:14:03,580 --> 00:14:08,650 So in that way, I can get all of these ports information on one port. 130 00:14:09,430 --> 00:14:12,000 So that is done via this. 131 00:14:12,940 --> 00:14:21,980 First, we need to set up rules and these packets will first verify this chain preloading chain. 132 00:14:22,120 --> 00:14:26,330 So after that, they will go to the post chain then. 133 00:14:26,350 --> 00:14:31,040 Then it will go to the destination we now are redirected to. 134 00:14:31,540 --> 00:14:35,400 So we'll see this configuration in the next video. 135 00:14:35,510 --> 00:14:40,580 Bypassing it was for no, that's only speak to the theory. 136 00:14:41,590 --> 00:14:47,030 Now, I have found this website, which is the card that they have the diagram also. 137 00:14:47,410 --> 00:14:52,810 So we are getting that incoming connections and we are proud of that. 138 00:14:53,020 --> 00:15:00,350 And if you want to deliver to this local address, I mean, in your own computer, but different. 139 00:15:00,350 --> 00:15:10,690 But you can deliver before the shooting or if you do not want to route that packet into your local port, 140 00:15:10,690 --> 00:15:14,620 then you can directly proportional to this outside world. 141 00:15:16,000 --> 00:15:18,040 OK, I will say an example. 142 00:15:18,190 --> 00:15:25,750 Suppose, uh, there is there so take this example again as an example. 143 00:15:26,020 --> 00:15:27,650 This is the village mission, right? 144 00:15:27,970 --> 00:15:36,700 So now I am going to send the packet to my colleague next mission so those packets will go for standard 145 00:15:36,700 --> 00:15:37,900 operating rule. 146 00:15:38,530 --> 00:15:43,080 If we attempt to drop these packets, it will be dropped. 147 00:15:43,600 --> 00:15:51,160 And before preloading, after pirouetting and before posting, no, I can drop this package to my local 148 00:15:51,160 --> 00:15:52,120 processor. 149 00:15:52,270 --> 00:15:53,970 Uh, Netcare, 2004. 150 00:15:54,250 --> 00:15:57,160 So are these data sorry. 151 00:15:57,520 --> 00:16:01,840 Are this data from the Loston can be captured in the network. 152 00:16:02,030 --> 00:16:02,620 Two thousand. 153 00:16:02,950 --> 00:16:08,810 And then I can forward to another computer, uh, Windows XP machine. 154 00:16:09,520 --> 00:16:18,610 So this is a pirouetting and so in coming packets will go into this preloading chain and then if you 155 00:16:18,610 --> 00:16:22,420 want to send it to local port, you can send it. 156 00:16:22,420 --> 00:16:28,480 Otherwise it will go to the post routing rules and then it will go to the actual destination. 157 00:16:28,990 --> 00:16:31,510 You can also stop the process here. 158 00:16:31,520 --> 00:16:35,450 I mean, Pacard, the sending the package here, you can also send it to the Port Authority. 159 00:16:35,830 --> 00:16:36,670 This is the principle. 160 00:16:36,910 --> 00:16:40,830 And the next video, what we are going to do is we are stopping it here. 161 00:16:42,490 --> 00:16:43,860 So that's that this you go. 162 00:16:43,870 --> 00:16:50,200 I hope this might sound confusing, but in the next few days we will do the practical and you will have 163 00:16:50,200 --> 00:16:53,410 much more gratification than this, uh, theory will be. 164 00:16:54,400 --> 00:17:01,000 So I highly suggest you to read this article, and this article is very interesting. 165 00:17:01,000 --> 00:17:09,850 And if you want to set the table for some more computers and like a smart organization and this website 166 00:17:09,850 --> 00:17:11,050 is very much useful. 167 00:17:12,010 --> 00:17:13,390 So that's all for this review. 168 00:17:13,390 --> 00:17:14,560 I hope you have understood.