Here you can find all lookup results for loopback IP address 127.0.0.21 which is located in 127.0.0.0/8, a reserved range for loopback addresses to the local host (RFC 6890).
IP address 127.0.0.21 is registered as a loopback interface address, which is also known as
localhost or local host. In computer networking, localhost is a hostname that means
this computer. It is used to access the network services that are running on the host via its
loop back network interface. Using the loop back interface bypasses any local network interface
This type of address is also used as a means to validate that a locally connected physical networking card is working as expected and the TCP/IP stack is installed.
This local mechanism is useful for testing software during development, independently of any networking configurations. For example, if a computer has been configured to provide a website, directing a locally running web browser to http://localhost or http://127.0.0.1 may display its home page.