What Is IP?

what is IP address? what is IP address space, what is private IP address space?

• private network is a network that uses private IP address space(What is it?).These addresses are commonly used for home, office, and enterprise local area networks (LANs),

• Answer:

  IP addresses by themselves are just unique identifiers (hence "address") used to identify each computer or device on a network. They specifically apply to networks using the IP protocol, which is really all most people will encounter. There are 2 IP address protocols in use: IPv4, and IPv6. IPv4 is vastly more common today, but networks are slowly starting to migrate. The basic premise of IP addressing is that each computer connected to a network must have a unique address. In IPv4, all addresses are 32 bits long, broken into 8-bit chunks separated by periods (i.e. 1.1.1.1 - 255.255.255.255). Back in the day, there were enough addresses that everyone on the Internet could have their own unique address, and there were plenty to go around. Then the Internet got full. Because of the "shortage" of IP addresses (there are 232 possible IPv4 addresses), the idea of "private addresses" were introduced. These are the following blocks: 10.0.0.0/8 172.16.0.0/12 192.168.0.0/16 The /8, /12, and /16 refer to the subnet mask, which is used to determine how large the network can be before it must be split up. The subnet masks above are 8, 12, and 16 bits, yielding maximum network capacities of 224, 212 and 28 devices, respectively. Note that for the 2nd and third groups, there are multiple networks available within this range (i.e. 192.168.0.0 and 192.168.1.0 must be on separate networks, but 10.0.0.0 and 10.0.1.0 don't have to be). (Note that IPv6 by contrast uses 128-bit addressing, which leaves a huge address space available so that we might once again all have unique public IP addresses.) In order to make these "private" networks useful, many networks have employed http://en.wikipedia.org/wiki/Network_Address_Translation (NAT), or as it is more commonly seen http://en.wikipedia.org/wiki/Port_address_translation (PAT) (sometimes also referred to as "NAT Overload"). Most devices which claim to support NAT are really using PAT. The idea behind PAT is that the router can mask away a large number of private IP addresses to a single public IP. It does so by mapping each internal/private IP address to the public IP address and a specific port (as usually defined in the TCP or UDP protocols). This way, you can have a network containing multiple devices (e.g. 10.0.0.1, 10.0.0.2, 10.0.0.3, etc), and they will all be represented by the single router with a public IP address (e.g. 11.32.123.4). The end result of this is that many people can re-use the same private IP address ranges without conflict on the globally connected Internet. For example, almost all home routers use 192.168.0.0/8 or 192.168.1.0/8. By employing PAT, we are all able to use these IP ranges without having conflicts when our computers actually talk over the Internet. The computers at each end are talking only to the router with the public IP, which then keeps track of where to forward the traffic on the private network based on the incoming port from a higher level protocol (i.e. TCP or UDP).