WEBVTT 00:00.810 --> 00:08.490 To a technical protocols, you need to understand the basics of network, computer and computer networking. 00:09.030 --> 00:16.320 The more you understand how common networks are pooled and functions, the easier it will be to apply 00:16.320 --> 00:21.540 that knowledge to capturing, analyzing and exploiting new protocols. 00:23.180 --> 00:32.080 These course I will introduce basic network concepts you will encounter every day when you, uh, you 00:32.160 --> 00:33.900 are analyzing it through protocols. 00:34.080 --> 00:42.330 I will also lay the groundwork for a way to think about or protocols make it easier to find previously 00:42.330 --> 00:48.870 unknown security usurious during your analysis network architecture and protocols. 00:50.220 --> 00:54.300 And to me, right here, something actually, this is the network. 00:55.500 --> 01:05.090 And we have, for example, uh, Workstation actually tells us. 01:06.720 --> 01:09.030 So this is the work station, for example. 01:11.220 --> 01:12.320 And here. 01:13.640 --> 01:21.650 Um, so let's at uh, one looks at well, left up again here, for example, and. 01:27.140 --> 01:28.760 And workstation here. 01:37.590 --> 01:41.490 And, for example, it's a server again. 01:43.560 --> 01:48.180 This is a server and it's another server. 01:50.480 --> 01:52.010 Here so. 01:53.150 --> 02:02.630 These are the networks, so we will introduce more deeply about them so that this figure shows actually 02:03.530 --> 02:11.240 five nodes connected with a common network, so each node might have a different operating system or 02:11.240 --> 02:17.360 hardware, but as long as each node follows a set of rules or network protocol. 02:19.790 --> 02:20.140 Surely. 02:22.240 --> 02:22.430 Oops! 02:23.330 --> 02:25.240 It's right down here. 02:26.430 --> 02:27.330 OK. 02:29.490 --> 02:32.460 Network protocol, network protocol. 02:33.950 --> 02:34.340 Here. 02:46.430 --> 02:53.840 So, um, but as long as the whole of the set of rules or an extra protocol, it can communicate with 02:53.840 --> 02:57.320 the other nodes on the network, communicate correctly. 02:57.320 --> 03:02.390 All nodes on network must understand the same network protocol. 03:02.780 --> 03:09.110 And it's our protocol serves many functions, including, uh, one or more, for example. 03:09.440 --> 03:12.620 Let's write it down here. 03:13.280 --> 03:14.240 Uh, text. 03:18.120 --> 03:18.430 So that. 03:22.690 --> 03:24.270 So, um, mobs. 03:29.190 --> 03:29.580 So. 03:31.360 --> 03:33.670 Network protocol functions. 03:34.690 --> 03:35.020 Yes. 03:37.740 --> 03:40.080 Network protocol. 03:41.050 --> 03:41.650 Functions. 03:45.470 --> 03:48.080 So what is what network network? 03:49.760 --> 03:56.450 I already told you that network critical serves many functions, including including, for example, 03:56.660 --> 04:05.450 maintaining mean terror and maintaining, uh, maintaining a station, states base stations state. 04:06.440 --> 04:13.770 So now what maintenance assurance that means these protocols typically implement mechanisms to create 04:13.790 --> 04:18.020 new connections and terminate existing connections. 04:18.780 --> 04:24.990 Um, create new connections and terminate. 04:25.640 --> 04:26.930 Actually, can I do like that? 04:27.470 --> 04:30.070 Yes, and terminate it. 04:31.890 --> 04:34.770 Meaning connections here. 04:35.460 --> 04:44.820 So these are the functions of network protocols, and this is also identifying nodes for addressing 04:45.930 --> 04:46.230 what's. 04:49.140 --> 04:50.040 I know it's. 04:54.950 --> 04:59.500 So what Identifying the most for addressing means. 05:00.680 --> 05:04.520 OK, so data must be um. 05:06.240 --> 05:06.750 Troy, this. 05:10.890 --> 05:21.090 Others think so data the main must be addressed threat and transmits it to correct not on a network. 05:21.450 --> 05:29.850 So saying some protocols implement and addressing mechanism to identify specific nodes or group groups, 05:29.880 --> 05:33.360 actually some protocols. 05:34.780 --> 05:42.960 Actually, not some put yes, some protocols implement, implement and addressing mechanism and the 05:43.020 --> 05:45.130 racing mechanism. 05:47.280 --> 05:53.390 Mechanism to identify to widen ify spaces. 05:54.750 --> 06:05.670 Specific UM, nodes or groups of nodes, lots of or nodes, nodes or. 06:06.630 --> 06:10.020 Rural groups of lots. 06:13.070 --> 06:15.860 And here it is. 06:17.960 --> 06:27.560 And if a political serves many function, as you know, one of them is controlling for controlling controlling 06:28.580 --> 06:29.030 flow. 06:30.610 --> 06:38.440 So the amount of data transferred across a network is limited, politicos can implement ways of managing 06:38.560 --> 06:43.120 data flow to increase throttled and reduced latency. 06:44.170 --> 06:51.160 And we have also guaranteeing the order of trance transmitted data. 06:54.160 --> 07:05.020 The order of transmitted data, so many networks do not guarantee that the order in which the data is 07:05.020 --> 07:12.850 sent will match the order in which it's received a protocol can be reorder the data to ensure is delivered 07:13.120 --> 07:14.560 in the correct order. 07:14.980 --> 07:17.140 And we also have detecting. 07:18.630 --> 07:21.660 And correcting or errors? 07:23.350 --> 07:23.890 Errors. 07:24.930 --> 07:30.900 So many networks are not hundred presence, reliable data can be corrupted. 07:31.230 --> 07:36.400 It's important to detect corruption and ideally correct it. 07:36.990 --> 07:44.840 And we have to have lastly formatting, formatting and encoding data. 07:46.410 --> 07:52.290 Data, so the data isn't always in the form of suitable for transmitting on a network. 07:52.830 --> 08:03.990 So a protocol to specify ways of encoding data, such as encoding English text into English text, uh, 08:04.080 --> 08:08.730 into my binary files. 08:10.580 --> 08:11.920 So, um. 08:13.750 --> 08:16.480 We have all seen health protocol suites here. 08:16.920 --> 08:19.240 Let's come here so. 08:21.570 --> 08:26.670 The CPI is the de facto protocol that modern networks use. 08:31.460 --> 08:33.030 He's simply a pea. 08:34.210 --> 08:34.740 So. 08:37.490 --> 08:43.010 These protocols, actually, I'll you you can think of this party IP as a single protocol. 08:43.430 --> 08:48.920 It's actually a combination of two protocols, so that's what this trip means. 08:50.460 --> 08:52.200 And here next. 08:56.540 --> 09:04.920 But here this key IP is, uh, combination is home.