how to use backup (secondary) DNS?
My hosting provider provided me two IP addresses. Both are different, but they appear to point to the same server. They are used for creating nameservers, so that I can give my nameservers to my client's accounts when setting them up, so their domains point to my server.
If the server goes down, what's the point of having the second nameserver, considering that both nameservers point to the same server, and it would be down anyway? What the hell is the point of the second one? Even though the second IP address for the second nameserver is different, how does it point to the same server? I.e. are the two addresses that comprise the nameservers, just two IP addresses on my host machine, configured as eth0 and eth0:0? Or does the second address point to a completely different DNS system which in-turn redirects you to your page if it's up?
Is this where "secondary dns" comes into play? Should the second nameserver point to a backup DNS server hosted elsewhere? How would I go about doing this? I just don't understand.