An IP (Internet Protocol) address is a unique identifier for a node or host connection on an IP network. An IP address is a 32 bit binary number usually represented as 4 decimal values, each representing 8 bits, in the range 0 to 255 (known as octets) separated by decimal points. This is known as "dotted decimal" notation.

Question: What the hell is a node?

140 .179 .220 .200
10001100.10110011.11011100.11001000

2. A node is just 1 particular point on a network, or an ip address...

the difference between the numbers is a difference in base,, decimal is base 10, binary is base 2

so 140 == 1000 1100 binary

Quick and dirty :

think of it this way, what is 140 ? 140 means there is 1 100, 4 10's and 0 1's, each a multiple of 10, binary is no different, but the multiples are 2

so the places for an 8 bit binary number are 128 64 32 16 8 4 2 1, so 1000 1100 means 1 128, 1 8, 1 4, add those up: 128 + 8 + 4 = 140.

179 = 10110011 or one 128 + one 32 + one 16 + one 2 + one 1 = 179

You might also by the way see hex, which is based on multiples of 16, works the same way except there are digits for 10-15 (a, b, c, d, e, f respectively), quick way from binary to hex is to take binary in groups of 4, so 179 would be 10110011 or b3.

Neb

3. For binary:

128 | 64 | 32 | 16 | 8 | 4 | 2| 1
---------------------------------------
1 | 0 | 0 | 0 | 1| 1 | 0| 0 = 140.

4. 1 node = 1 device. ie your computer is a node. If you have a plug and play microwave sitting on your network, it is 1 node. Any single endpoint is a node.

the conversion was chaning 140 to binary, 179 to binary, 220 to binary, and 200 to binary. There have been a couple tutorial written on it. Just search google for decimal to binary conversion. either that, or open up the calculator on a windows machine. Put it in scientific mode (View-->Scientific) type in the number (140). Then click the radio button next to Bin (Binary). It wil give you the binary number, and requires no thought... Do that for each of the 4 numbers, and you will have you 32 bit number....

5. Dr. Toker. I see your question has been answered, is there another part to this question?

6. nebulus200 showed you the sum of weights method of decimal to binary conversion, I thought it might be helpful to show you a second way, called the division by two method.

This is simple, simply take your decimal number, divide by two, and write down your remander, then divide your answer by 2, write down the remainder, and so on till you can no longer divide by 2 without getting fractional numbers. Here is an example:

Convert 12 in decimal to a binary number equivalent

12/2 = 6 remainder 0
6/2 = 3 remainder 0
3/2 = 1 remainder 1
1/2 = 0 remainder 1

Now the first remainder you got is your LSB (least significant bit)
The last remainder you got is your MSB (most significant bit)

So you would write out the remainders like so:

1100 and that is the binary equivalent of your decimal number 12.

To convert from binary to decimal quickly my teacher showed me a trick, like folows:

1100

multiply the first bit by 2, 1 x 2 = 2 and add the next bit, 2 + 1 = 3, multiply the result by 2, 3 x 2 = 6, add the next bit which is 0, 6 + 0 = 6, multiply the result by 2, and add the next bit, 6 x 2 = 12 + 0 = 12. So basicaly you multiply the MSB by 2, add the next bit, multiply the answer by two and add the next bit, till you get to the end. Another example:

10010110

2 x 1 = 2 + 0 = 2 x 2 = 4 + 0 = 4 x 2 = 8 + 1 = 9 x 2 = 18 + 0 = 18 x 2 = 36 + 1 = 37 x 2 = 74 + 1 = 75 x 2 = 150 + 0 = 150 so the answer is 150.

7. To elaborate on soulemans point. Its not just an end point that is a node. A node in networking is one devioce. This can be router switch hub etc etc. Anything really apart from wires!

8. Nebulus200: quick way from binary to hex is to take binary in groups of 4, so 179 would be 10110011 or b3.
I should have elaborated a little better: 10110011, split into groups of 4, so you have 1011 and 0011, then just convert like you normally would to decimal,
1011 binary = 11 decimal = b hex (a=10, b=11, c=12, d=13, e=14, f=15)
0011 binary = 3 decimal = 3 hex

Anyway, I can rest easier now that I actually explained what I meant, I tend to assume to much

Neb

9. Yes, a node is actually any network ressource that uses TCP/IP with a IP adress.

IP adress are in a format of 4 bit in decimal 140.25.145.21. With a decimal value of 0 to 255 max described as the maximum value of a 8 bit binary number.

128 | 64 | 32 | 16 | 8 | 4 | 2 | 1
----------------------------------------
0 0 0 0 0 0 0 0 = 0
0 0 0 0 0 0 0 1 = 1
0 0 0 0 0 0 1 0 = 2
0 0 0 0 0 0 1 1 = 3
0 1 0 0 0 1 0 1 = 69 dude
and so on...

You could also complicate things by going into describing the differences between and IP Classes and Subnetting, a quite interesting concept to read !

See ya !

10. Sorry to just jump in, but I FINALLY get the basics of converting the IP address. I have often seen explanations on this, but they always just confused me more. Thank you all for the great group of explanations and examples!

#### Posting Permissions

• You may not post new threads
• You may not post replies
• You may not post attachments
• You may not edit your posts
•