DNS Question

I couldn't find a better place for this question, so I'm plopping it here. Hope it's ok.

Most domain names has 2 dns servers listed going to their hosting server.

Example:
dns1.mainserver.com
dns2.mainserver.com

Now, if I add 2 more dns to another server, kindof a backup server like this:
dns1.mainserver.com
dns2.mainserver.com
dns1.secondaryserver.com
dns2.secondaryserver.com

Would the user only get to the secondary server only if the dns for the first 2 fails, or would it query all 4 dns server, and whoever responds first is where the user is directed?

For a registrar, I'm using register.c$m for this example.

Thanks!

DNS uses a round robin algorithm. It would more less randonly give out any from the list.

Mike

Is there a way to have a backup website hosting, just in case the primary fails?

Is there a way to achieve this?

Thanks!

to my understanding, only the first 2 dns servers are down, your third dns server will then be able to get the dns request

do you want backup site hosting, or backup dns? Sounds to me like you are worried about your dns machines becoming unavailable. First thing that comes to mind here is, who is your web hosting company, or are you doing this yourself. We used to have our own server farm with redundant web servers, dns machines and database servers. Now we outsource all of that. Bottom line, use a reputable host and focus on the things that matter, like growing your business.

Some large comanies use Big IP for example to point to the backup website but if you don't have that type of tool you just need to change the IP address of your (A name) or (c name) on your dns server.