Today on a site I have found the opinion:
"Loopback interfaces are logical and maintained within software and *NEVER* go down as long as the router is turned on and operating (unless you "no" them).
Anyone who uses a subinterface as a loopback interface is a fool and needs to be taught a lesson, and shouldn't have a job as a network administrator :-)"
On another site I found proc about the lookback interface cose this improve security and scalability.
So I have the question: To use or do not use the loopback interface in a production environment (not in a test lab)?
Any opinion welcome!
