Why there is separate loopback address?
Why there is separate loopback address?
Therein lies the simplicity of it because, if an interface does go down, that IP is no longer used as it become unavailable so, how can you use that IP now for updates if it is down yet, others are available that I can get to via alternative paths. That is were the Loopback comes in to play. Having an Address that doesn’t really ever go down due to failure allows these routing updates to occur by, identifying the fault, calculating the best alternative path and subsequently routing traffic around the failed link and/or device. This is what is meant by fault detection, isolation and convergence.