Which range is the loopback address range for IPv4?

Which range is the loopback address range for IPv4?

• A. 127.0.0.0/8
• B. 169.254.0.0/16
• C. 192.168.0.0/16
• D. 255.255.255.0/24

Answer: (A)

Loopback addresses are reserved for testing and communicating with the local machine; packets addressed to these addresses stay on the device and are not sent onto the network. The IPv4 loopback range is 127.0.0.0/8, meaning any address from 127.0.0.0 through 127.255.255.255 can be used for this purpose, with 127.0.0.1 the most common example. The other ranges serve different purposes: 169.254.0.0/16 is link-local (APIPA) used when DHCP isn’t available, 192.168.0.0/16 is private LAN addressing, and 255.255.255.0/24 resembles a subnet mask rather than a host address range, so it isn’t a loopback range.

Loopback addresses are reserved for testing and communicating with the local machine; packets addressed to these addresses stay on the device and are not sent onto the network. The IPv4 loopback range is 127.0.0.0/8, meaning any address from 127.0.0.0 through 127.255.255.255 can be used for this purpose, with 127.0.0.1 the most common example. The other ranges serve different purposes: 169.254.0.0/16 is link-local (APIPA) used when DHCP isn’t available, 192.168.0.0/16 is private LAN addressing, and 255.255.255.0/24 resembles a subnet mask rather than a host address range, so it isn’t a loopback range.