127
(not so sure).. i think this block is reserved for loopback address on PCs
Loopback address
127.0.0.1 is the loopback address in IP.... or in the (slightly modified) words of Dorthy Gale when she returned from Oz "There's no place like 127.0.0.1"
The loopback address for each machine is 127.0.0.1, regardless of how many machines are on the network.
Local loopback address
127.0.0.1
The entire 127 range (127.0.0.1 to 127.255.255.254) is considered the LOOPBACK address range, and is in the class A network. This address range or block is reserved just for local testing.
In IPv4, the loopback address is 127.0.0.1. In IPv6 it is ::1.
host to all
The usual loopback address is 127.0.0.1 (but any address between 127.0.0.0 and 127.255.255.255 can be assigned to it) The address is also known as http://localhost/. In order to test the connection however a server would have to be installed. Apache is an example of a web based software server.
The address 127.0.0.1 is commonly referred to as "localhost" or the "loopback address." It is used to establish a connection to the same machine or computer that a user is working on, allowing for testing and development of network applications without the need for an external network. This address is part of the IPv4 standard and is reserved for loopback purposes.
There are several IP addresses that are special in one way or another. These addresses are for special purposes or are to be put to special use.Addresses significant to every IP subnet Network AddressBroadcast AddressAddresses significant to individual hosts Loopback AddressSpecial Addresses of Global Significance Private AddressesReserved AddressesLOOPBACK ADDRESS (127.0.0.1)The 127.0.0.0 class 'A' subnet is used for only a single address: the loopback address 127.0.0.1. This address is used to test the local network interface device's functionality. All network interface devices should respond to this address. If you ping 127.0.0.1, you can be assured that the network hardware is functioning and that the network software is also functioning.