Loopback IP Addresses
The Loopback IP Addresses This means “I am Everywhere”
When we say it loopbacks, were referring to the IP address 127.0. A self-referential address that all device to communicate in the local environment its running on It enables a very handy local test environment allowing you to check network connectivity, configure networking interfaces and work with up or listening services.
The Most Common Loopback IP Addresses
127.0.0.1 is the most common loopback IP This is for the loop back traffic, which can not be routed on internet. Any packet sent to this address will be delivered back on the same device, even if no other data is written with that IP.
Why Use a Loopback IP?
- Testing Network Connectivity:
- Checking if the network interface and TCP/IP stack is working.
- Ping 127.0.0.1(ping to itself, ie if Loopback interface is operating)
Setting up the Network Interfaces
- Loopback interfaces are used to give IP addresses on devices which may lack physical network interface.
- In stateless setups such as virtual machines, routers and network devices.
Running Local Services:
- Most services (e.g: Web servers, DBs) can be configured to listen on the loopback interface
- Read service is limited to the local host, providing an extra layer of security
Other Loopback IP’s
- 127.0.0.1 is the most well known but other loopback IP’s :
- 127.0.0.0: This address is also reserved for loopback interfaces, meaning that any packet sent here will be routed back to this machine as though it was returning from an external source and packets received arriving through a network of some sort;
- 127.0.1 to 255So used for loopback addresses;
Loopback Interfaces
Loopback interfaces are the network interface that does not exist physically it is just a virtual representation by an operating system. They are meant for loopback traffic. Generally, each operating system creates a default loopback interface but you can create extra loopbacks as well.
That’s it
The first and foremost thing in network communication is Loopback IP,s. You have now learned how to test network reachability, set up your network interfaces and serve local applications.
