Cache of BIND is kinda of a "Black hole" for me. I know about TTL and that it can be overridden. I know that there's a way to dump cache into a file that could be viewed in a text editor. But, still, lots of things are in the dark. I've read that once you reboot, the cache is lost. Then why to build the cache from scratch each time you turn on your computer? What, like BIND's building its cache for a few hours when the server is on and then simply loose it? That doesn't make sense. Why it can't be kept in a file or in a database? Is it a limitation or something good? Unfortunately, I didn't find in books or on the Internet clear information about all of this. So please explain it to me in simple English OR just provide the links to the relevant source of information.