Loopback interface

A Loopback Interface is a virtual interface on a network device that is used to communicate with itself.
- Primarily used for diagnostics and troubleshooting to ensure other processes and protocols are working.
- Often they are used on networking devices to ensure there is an IP address that is unique to that device, and not dependent on an active link, for management purposes
- In Dynamic Routing Protocols like OSPF, it can be used when deciding router priority or identification
Example addresses are often 1.1.1.1, 2.2.2.2, etc., but these are real addresses on the internet and should not be used
- A better example might be 10.255.0.1, 10.255.0.2, etc.
This is not the same as Loopback addresses, which are defined in RFC 1918 with the range 127.0.0.0/8, reserved block from Class A

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