WEBVTT 00:00.120 --> 00:09.620 In this lecture, we will learn about all the three states of a port and the first scan. 00:09.640 --> 00:10.190 Right? 00:10.200 --> 00:14.460 So let me scan my target network first. 00:14.460 --> 00:15.990 So type and map. 00:15.990 --> 00:27.030 Now hyphen uppercase f now write the URL or IP address hyphen uppercase f flag means faster the default 00:27.030 --> 00:37.680 and map scan scans the most popular thousand ports, whereas the fast scan only scans the most popular 00:37.680 --> 00:39.000 100 ports. 00:39.000 --> 00:45.090 So this scan is ten times faster than the default and MAP scan. 00:45.090 --> 00:46.290 So let me hit enter. 00:46.980 --> 00:49.650 As you can see, scan is complete. 00:49.650 --> 00:52.980 Fast scan scanned a hundred ports. 00:52.980 --> 00:55.830 As you can see, 91 ports are open. 00:55.830 --> 01:02.010 So re closed and remaining nine ports are either open or filtered. 01:02.100 --> 01:09.110 As you can see here, we have a few open ports such as FTP and search. 01:09.300 --> 01:09.750 Right. 01:09.750 --> 01:13.290 So what does an open port mean? 01:13.290 --> 01:18.750 And open port means it is open and available to everyone. 01:18.750 --> 01:22.050 It is accepting new connections. 01:22.380 --> 01:28.590 Open ports can be problematic if they are not protected properly. 01:28.590 --> 01:33.450 There are some ports that hackers target the most. 01:33.600 --> 01:37.890 Port number 21 and 22 are among them. 01:37.890 --> 01:44.040 Port number 21 runs FTP and 22 runs SSH service. 01:44.100 --> 01:44.400 Right. 01:44.400 --> 01:51.330 As you can see now, these two ports allow us to access the servers remotely. 01:51.360 --> 01:56.310 You just need to enter the correct username and password. 01:56.310 --> 02:01.200 Then we can use our access the server remotely. 02:01.200 --> 02:07.200 Now what does an open port mean from a hacker's perspective? 02:07.230 --> 02:12.150 If a port is open, then anyone can access it, right? 02:12.150 --> 02:15.750 Whether it is the system, admin or attackers. 02:15.750 --> 02:24.930 Let's say if port number 21 or 22 is open, then attackers can brute force FTP and SSH services. 02:24.930 --> 02:33.150 If login credentials are weak, then username and password can be cracked very easily. 02:33.180 --> 02:39.660 Remember, hackers can only launch attacks if port is open, right? 02:39.660 --> 02:47.790 If it is filtered or closed, then it makes attacks irrelevant to a great extent. 02:48.060 --> 02:52.830 This is why a map is so important for attackers, right? 02:52.830 --> 02:55.830 It provides the openings, right? 02:55.830 --> 03:03.070 Once attackers know that the port is open and available, then attacks can be launched. 03:03.450 --> 03:06.150 Now a second state is filtered. 03:06.150 --> 03:16.740 Filtered means port is protected by a firewall only the authorized devices can access the port and third 03:16.740 --> 03:18.330 state is closed. 03:18.330 --> 03:23.070 If a port is closed, then it means it is closed. 03:23.070 --> 03:25.980 No one can access or use it.