1
00:00:00,390 --> 00:00:00,750
‫OK.

2
00:00:01,320 --> 00:00:06,960
‫I know there are a lot of terms and conditions, so let's just break it down with a Real-World scenario.

3
00:00:07,940 --> 00:00:15,650
‫Although the standard for a and B-Class network specify eight and 16 bit masks, respectively, it's

4
00:00:15,650 --> 00:00:24,230
‫common to assign non-standard masks for subnet, resulting in much more limited address bases, right?

5
00:00:24,320 --> 00:00:34,130
‫For example, using 10 Dot Exact Why-Why zero size 24 results in 256 host company subnets, right?

6
00:00:35,000 --> 00:00:38,300
‫So this is done for scalability and, of course, security.

7
00:00:39,380 --> 00:00:44,840
‫OK, so we're the system administrators in Company X and ready to build.

8
00:00:45,710 --> 00:00:52,610
‫We have decided to use one nine two two one six eight x not X as a private IP address base for our company.

9
00:00:53,780 --> 00:01:03,510
‫If we use the natural mask 255.255.255.0 2.0, that means we use the first 16 bits for Network I.D..

10
00:01:05,000 --> 00:01:06,800
‫And we'll have a single network.

11
00:01:07,980 --> 00:01:13,140
‫So in this case, we can address 65000 536 devices in this network.

12
00:01:14,190 --> 00:01:19,710
‫Of course, the first IP in the last IP we're not allowed to use, so the number of IP addresses is

13
00:01:19,710 --> 00:01:23,310
‫actually sixty five thousand five hundred thirty six minus two.

14
00:01:23,340 --> 00:01:29,310
‫You do the math, but in practice for ease of use, it's pretty much used as the power of two.

15
00:01:30,660 --> 00:01:39,060
‫So you can use an IP address in this network from 192.168.0.1, who one nine two two one six eight two

16
00:01:39,060 --> 00:01:40,680
‫five five two five four.

17
00:01:41,980 --> 00:01:48,310
‫But we need to have different networks, one for the managers, one for the developers, one for the

18
00:01:48,310 --> 00:01:56,050
‫servers, etc. So for the sake of our use and our sanity, let's use the next eight bits for subnets.

19
00:01:57,400 --> 00:02:02,560
‫In this case, we have a subnet mask of 255.255.255.0.

20
00:02:03,580 --> 00:02:10,270
‫Eight bits for Senate and 24 bits for the network, I.D. and total, eight bits left for addressing

21
00:02:10,270 --> 00:02:12,360
‫the devices under the subnet.

22
00:02:13,150 --> 00:02:13,900
‫So as a result.

23
00:02:15,020 --> 00:02:17,390
‫We can create 256 subnet.

24
00:02:18,430 --> 00:02:21,730
‫And address 256 devices for each one.

25
00:02:23,140 --> 00:02:29,260
‫Now we have 256 address ranges for 256 sub networks.

26
00:02:30,700 --> 00:02:34,240
‫So the table here shows a few examples of our potential sub networks.

27
00:02:35,210 --> 00:02:40,490
‫The red colored blocks are added to the network ID as subnet identifiers.

28
00:02:41,420 --> 00:02:44,720
‫The rest of the eight bits are used as the host IDs.

29
00:02:46,170 --> 00:02:54,870
‫In the four block decimal notation, the third block identifies a sub network and the last block identifies

30
00:02:54,930 --> 00:02:59,270
‫the host, so breaking it down, it's much simpler now, isn't it?

31
00:02:59,850 --> 00:03:00,330
‫Excellent.

32
00:03:00,360 --> 00:03:00,950
‫Let's move on.