I made some calculations for IP

[tanush_89]

I made some calculations for IP and found out this :-


IP can range betwee0 0.0.0.0 to 223.255.255.255

So by permutation we get total of 4,53,49,632.

So at any instant maximum 4,53,49,632 computers and sites can only come /be online (excluding the ip's which are allocated to specific) sites.


And if we include that then the no. will reduce further.

I think only US would be using 4.5 carore ips every second.



So where am I making a mistake.


Coz the usage is much much more.

[piyush gupta]

See this list for detail knowledge of allocation of IP addresses

http://en.wikipedia.org/wiki/IPv4#Addressing

IPv4 uses 32-bit (4-byte) addresses, which limits the address space to 4,294,967,296 possible unique addresses. However, some are reserved for special purposes such as private networks (~18 million addresses) or multicast addresses (~1 million addresses). This reduces the number of addresses that can be allocated as public Internet addresses. As the number of addresses available are consumed, an IPv4 address shortage appears to be inevitable.
This limitation has helped stimulate the push towards IPv6, which is currently in the early stages of deployment and is currently the only contender to replace IPv4.
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IPv4 uses 32-bit (4-byte) addresses, which limits the address space to 4,294,967,296 possible unique addresses. However, some are reserved for special purposes such as private networks (~18 million addresses) or multicast addresses (~1 million addresses). This reduces the number of addresses that can be allocated as public Internet addresses. As the number of addresses available are consumed, an IPv4 address shortage appears to be inevitable.

This limitation has helped stimulate the push towards IPv6, which is currently in the early stages of deployment and is currently the only contender to replace IPv4.

[ahref]

There are many people who use same ip to connect to internet, example small offices, cybercafe etc.

[mehulved]

Search wikipedia for NAT and dynamic IP, that will answer your question.

[Pathik]

yup ... not evy user has a static ip... and many broadband users hav the same ip... and ipv6 is also gonna be implemented...

[Faun]

NAT

[alok4best]

u'll understand when u'll learn about NAT..NAT allows multiple nodes to connect to Internet using same public IP,,this Network Address Translation(NAT) is done by your subnet...subnet is used at college campuses,offices etc etc..

[freebird]

but if ipv6 got implemented?then how do you read it a loong confusing line?
I Love IPV4

[Pathik]

do u remember ips of all the sites u visit!?? Wat r domain names for??

[freebird]

Yaar!just joking...ya while trying setting up lan i do try to remember IP addresses.

[lalam]

Alright here's another question i was confused as to how you derived the n value for the formula 2n-2 .I know the 8 bit stuff but whats beyond that has confused me a hell lot so any simple way that someone may make me understand?

[alok4best]

I'll tell u thw whole behind IPV4...there are 4 fields..each 8bit.seperated by dots.
so each field can have 2^8 values..now if u convert a decimal IP to binary u'll get stream of 1s and zeros.now the rule is that it shud be a formation in which a stream of 1s iz followed by zeros..for example say 11111100 is valid entry while 11011111 is not..i told a 8 bit example.but the rule applies to the whole 32 bit.

so if ur subnet is 255.255.255.0 u will have its binary equivalent as
11111111.11111111.11111111.00000000..
now if u want to calculate how many hosts this subnet can hold..u just have to count the number of zeros..which is in this case 8..so total number of hosts that this subnet can handle will be 2^8.
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now the nexy example which u can verify..open ur network connections and go to properties and there to TCP/IP...enter say 192.168.1.1 as ur IP. now as soon as u click in the subnet field u'll get an automatic value of 255.255.255.255.
U must be wondering why it happened even when u didnt enter anything here.The simple answer is 255.255.255.255 is equivalent to 11111111.11111111.11111111.11111111. now as I told earlier count the number of zeroes..how many..NONE...so 2^0=1...since only your computer(1 host) is connected on that subnet u got no zeros..the same thing happens in Universities,Organizations..there they have different value for subnet masks..and thus using Network Address Translation they can operate multiple nodes using single public IP..I hope I was able to make it clear for you..


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[anand.expert]

Originally Posted by tanush_89

I made some calculations for IP and found out this :-


IP can range betwee0 0.0.0.0 to 223.255.255.255

So by permutation we get total of 4,53,49,632.

So at any instant maximum 4,53,49,632 computers and sites can only come /be online (excluding the ip's which are allocated to specific) sites.


And if we include that then the no. will reduce further.

I think only US would be using 4.5 carore ips every second.



So where am I making a mistake.


Coz the usage is much much more.

The main reason is that the ip which is generally in use is the IP which has been provided by the Virtual Private Network (VPN).Like(192.168.x.x) or
(10.x.x.x)

Moreover there is a concept of Subneting which is used to effectively use the IP without any waste of it.