1
00:00:01,000 --> 00:00:05,000
So now let's do it in reverse, binary to decimal

2
00:00:05,000 --> 00:00:10,000
So in this example, if we were given this IP Address in binary notation

3
00:00:10,000 --> 00:00:12,000
how would you convert it to decimal?

4
00:00:12,000 --> 00:00:18,000
So using our table, the 1st bit is set on so that is the equivalent of a 128

5
00:00:18,000 --> 00:00:23,000
2nd bit is off, 3rd bit is on which equates to 32, 4th bit is off

6
00:00:23,000 --> 00:00:31,000
5th bit is on equates to 8, 6th is on equates to 4 and the last 2 bits are set off

7
00:00:31,000 --> 00:00:38,000
So 1st bit is a 128, 64 is not used, 3rd bit is 32, 4th bit is not used

8
00:00:38,000 --> 00:00:44,000
5th bit is 8, 6th bit is 4 and the last 2 bits are not used

9
00:00:44,000 --> 00:00:51,000
that gives us a 128 + 32 + 8 + 4 = 172

10
00:00:51,000 --> 00:01:01,000
So 10101100 in binary equals 172 in decimal

11
00:01:01,000 --> 00:01:10,000
Looking at the 2nd octet, we have 00010000

12
00:01:10,000 --> 00:01:15,000
So in our table, the 4th bit is set on and all the other bits are set off

13
00:01:15,000 --> 00:01:24,000
So this is the equivalent of 16, so 00010000 is equivalent to 16 in decimal

14
00:01:24,000 --> 00:01:31,000
by the same token, in the 3rd octet which is full of 0s except for the last bit

15
00:01:31,000 --> 00:01:37,000
that equates to 1 in decimal or if we populate the octet with binary 1s

16
00:01:37,000 --> 00:01:39,000
that is the equivalent of 255

17
00:01:39,000 --> 00:01:44,000
so that's another example of doing binary to decimal conversion