Communicate with the TCP/IP stack on the same host without sending packets to a physical network.
Which address is a representative loopback?
127.0.0.1 is the representative IPv4 loopback address. Traffic to it is handled within the same host.
Detailed explanation
0.0.0.0Incorrect. 0.0.0.0 is an unspecified address in contexts such as binding.
Incorrect. 0.0.0.0 is an unspecified address in contexts such as binding.
127.0.0.1Correct. 127.0.0.1 is the standard loopback address.
Correct. 127.0.0.1 is the standard loopback address.
169.254.0.1Incorrect. 169.254.0.1 is link-local.
Incorrect. 169.254.0.1 is link-local.
255.255.255.255Incorrect. 255.255.255.255 is the limited broadcast address.
Incorrect. 255.255.255.255 is the limited broadcast address.
Try it yourself
An example you can run in a temporary verification environment.
python3 -c "import ipaddress; print(ipaddress.ip_address('127.0.0.1').is_loopback)"Expected result
TrueKey points
- 127.0.0.0/8 is loopback
- 127.0.0.1 is the common value
- Traffic stays on the host
Notes
- Environment: Python 3 ipaddress / 外部通信なし
- Command output formatting can vary slightly by distribution or tool version.
- Run the example in a temporary directory or process when possible.
Foundation review
Read the scope first
Check whether the command acts on the current shell, a new process, an existing process, or a file.
Verify the observable result
Use the supplied command and compare the output with the expected result.