Benefits of Loopback Interface. As the loopback address never changes, it is the best way to identify a device in the network. The loopback interface is always up and it is reachable as long as the route to that IP address is available in the IP routing table. Hence you can use the loopback interface for diagnostics and troubleshooting purposes. Loopback IP Addresses. The IP address range 127.0.0.0 – 127.255.255.255 is reserved for loopback, i.e. A Host’s self-address, also known as localhost address. This loopback IP address is managed entirely by and within the operating system. Loopback addresses, enable the Server and Client processes on a single system to communicate with each.
Ifconfig Ipv4 Address
Learn how to configure loopback interfaces on cisco router.In this tutorial we will learn how to assign ip address on loopback interfaces.Loopback interfaces are logical interfaces or you can say virtual interfaces in cisco router.They are not real interfaces.That’s why they never goes down untill or unless the complete router itself goes down.Here using cisco packet tracer lab we will show you how to configure virtual interfaces or loopback interfaces on cisco router and use them in routing.
Configuration on Router R1:
here I am going to assign ip address on router real interfaces and also going to create virtual interfaces and loopback interfaces and assign ip address on loopback interfaces.
See or verify router interface ip address using below command:
Configuration RIP Routing on Router R1:
remember you also have to include network created by Virtual Interfaces what we call Loopback interfaces.