how can I find out how many global IP addresses are possible?
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how can I find out how many global IP addresses are possible?
Well an IP is in the format:
xxx.xxx.xxx.xxx
where xxx can be between 0 and 255. That is 256 numbers soooooo the answer is 256^4. Which is, ummm, 4294967296.
In IP v7 or whatever version is next there will be six lots of 3 numbers, ie xxx.xxx.xxx.xxx.xxx.xxx, which gives umpteen million address to every square meter of the planet. lol.
281,474,976,710,656 :D
well, you gotta figure, aol is probably taking up 50% of all the IP addresses available now :eek:
hahaha
Well,
I'm not a big math-wizz, but there are a few miscalculations:
First, in an IP-range the last address (x.x.x.255) is always a "multicast" address (or router-adress, don't remember exactly) wich can't be used. So that takes out some possibilities. Also x.x.x.254 is (as I recall) preserved.
Second, any address containing a 0 for any octet cannot be used.
(An octet is one x out of x.x.x.x, so there are 4 octets in an IP address).
Third: there are some internal ranges defined wich cannot be used "global". These start with 10.x.x.x, 172.x.x.x and 192.168.x.x (and even some others as I recall).
Fourth: the address 127.0.0.1 is used to define "localhost" wich is your own computer.
Fifth: I need to review my IP-courses :D as a lot of this knowledge has slipped my mind.
Sorry, "second" wasn't all true, but I do recall something like that...
You forgot one important thing..
Subnets ???
Every Ip number can be shared by a sub network using a proxy server. And one of them can again be shared ...and one of them can be shared again and one...
thinktank: You're right, BUT to the outside world it's all the same IP as the one connecting the others to the net...
If you want to calculate all the possible IP addresses (not excluding the ones mentioned as reserved above ^ :) ) then maybe you could use this.. what possible use this would be to *anyone* whatsoever is beyond me though!
- AurilusCode:Dim A as Integer, B as Integer, C as Integer, D as Integer
Dim F as Integer
F=FreeFile(1)
Open "IP.Txt" for Output as #F
For A = 0 to 255
For B = 0 to 255
For C = 0 to 255
For D = 0 to 255
Print #F, A & "." & B & "." & C & "." & D
Next D
Next C
Next B
Next A
Close #F