1 00:00:00,779 --> 00:00:07,117 In the previous video, we already determine the best prefix and the IP range we will use. 2 00:00:08,154 --> 00:00:13,846 We agreed we will use 10.10.10.0/27. 3 00:00:14,906 --> 00:00:20,469 Next in this video we are going to calculate the total IP and subnetmask. 4 00:00:21,327 --> 00:00:27,000 The total IP is 2 to the power of 32 minus by 27. 5 00:00:27,733 --> 00:00:35,098 32 minus by 27 is 5, and 2 to the power of 5 is 32. 6 00:00:35,811 --> 00:00:40,426 So the total ip for prefix /27 is 32. 7 00:00:41,519 --> 00:00:44,545 Next let’s calculate the subnetmask. 8 00:00:45,000 --> 00:00:52,417 The formula is 256 minus by total ip, and the total ip is 32. 9 00:00:53,008 --> 00:00:55,639 256 minus by 32. 10 00:00:55,940 --> 00:00:58,820 The result is 224. 11 00:00:59,634 --> 00:01:06,629 So the subnetmask is 255.255.255.224. 12 00:01:07,912 --> 00:01:12,000 Okay we have done with total IP and subntmask. 13 00:01:12,426 --> 00:01:16,231 Now let’s calculate the network ip and broadcast ip. 14 00:01:16,900 --> 00:01:21,137 Remember that network ip is always started with 0. 15 00:01:21,817 --> 00:01:28,468 The network for the next block subnet is 0 plus by the total ip, which is 32. 16 00:01:28,736 --> 00:01:30,661 The result is 32. 17 00:01:31,509 --> 00:01:38,516 The next block subnet, 32 plus by total ip again, the result is 64. 18 00:01:39,252 --> 00:01:46,420 Next block subnet, 64 plus by total ip again, the result is 96. 19 00:01:47,234 --> 00:01:54,426 Next block subnet, 96 plus by total ip again, the result is 128. 20 00:01:55,296 --> 00:02:06,863 Next block subnet, 128 plus by total ip again, the result is 160, 160 plus by total ip again, 21 00:02:07,175 --> 00:02:21,427 the result is 192, 192 plus by total ip again, the result is 224, and so on, until we reach 256 22 00:02:22,030 --> 00:02:29,610 Actually we don’t need to calculate until 256, but for learning, we are going to calculate 23 00:02:29,610 --> 00:02:31,607 until 256. 24 00:02:32,299 --> 00:02:38,675 Here 224 plus by total ip again, 32, the result is 256. 25 00:02:39,545 --> 00:02:42,611 Okay here we already reach 256. 26 00:02:42,611 --> 00:02:44,061 We can stop here. 27 00:02:44,473 --> 00:02:50,716 Next let’s calculate the broadcast ip. 32 minus by 1 is 31. 28 00:02:51,541 --> 00:02:55,580 Here is 63 because 64 minus by 1. 29 00:02:56,862 --> 00:03:10,541 Here 127, here 159, here 191, here 223, and here 255. 30 00:03:11,756 --> 00:03:15,839 Okay, so this is the block subnet for /27. 31 00:03:16,274 --> 00:03:24,062 Here we have block subnet 1, block subnet 2, block subnet 3, block subnet 4, block subnet 5 32 00:03:24,151 --> 00:03:28,973 block subnet 6, block subnet 7, and block subnet 8. 33 00:03:29,564 --> 00:03:32,171 So we have 8 block subnet here. 34 00:03:32,650 --> 00:03:35,848 We are free to use which block subnet we want. 35 00:03:36,216 --> 00:03:39,595 Let’s say we are going to use the first block subnet. 36 00:03:40,097 --> 00:03:49,595 So the network is 10.10.10.0, the third first number is not change and the last number is 37 00:03:49,595 --> 00:03:52,105 the result of our calculation. 38 00:03:53,945 --> 00:03:58,819 And then the broadcast is 10.10.10.31. 39 00:03:59,410 --> 00:04:03,706 Remember that network ip and broadcast ip will never can be used. 40 00:04:04,163 --> 00:04:10,484 So the ip that we can use is after network ip until before broadcast ip. 41 00:04:11,187 --> 00:04:24,265 So the ip range is 10.10.10.1, after 0 is 1, until 10.10.10.30, before 31 is 30. 42 00:04:25,034 --> 00:04:36,794 Okay, so for these 15 pc, we are free to use the ip from range 10.10.10.1 until 10.10.10.30. 43 00:04:38,043 --> 00:04:43,914 Okay I think enough for this video, in the next video, we are going to practice using 44 00:04:43,914 --> 00:04:45,279 packet tracer. 45 00:04:45,825 --> 00:04:49,047 Thankyou for watching and see you on the next video!