DNS name servers & hosts on the same server?

[belvin]

Every piece of information I could find on name servers says you need at least 2 : primary and secondary.

I understand the importance of this in networks. You don't want your site to be unreachable because your primary name server, located on another machine, is down.

But if you have a small (micro) hosting business and all your domains are hosted on the same physical machine, including your primary name server, is there a point in setting up a secondary name server?

If your primary name server is unreachable for some reason, hosts on the same machine will also be unreachable anyway... will a secondary name server on the same machine (or elsewhere) make any difference?

Thank you for any info on this obscure DNS thing.

 

[jamesyeeoc]

You are correct. If you have a single server with the hosting and DNS on it, and the server totally goes down (all services), then having a 2nd DNS server will be of no use. (total server failure)

If the single server remains running and the Apache service is running and serving up the web pages, but the Bind/Named service on it malfunctions, then having a 2nd DNS server would allow people to still browse the sites. (partial server functionality)

Some domain registrars 'require' that the domain have 2 name servers defined. Technically you can register 2 nameservers pointing to the same IP address (the single server), but in reality you do not get any sort of redundancy. (see first paragraph)

There are 'free' secondary name services on the internet, so you could still have a 2nd DNS server for your domains without having to invest money in a second server. Keep in mind that the hardware requirements for a server to just run DNS is fairly minimal. You *could* even get away with using an old junky P2 or P3, as long as you can load the Linux OS and have the Bind/Named service running. Configuration changes can be done manually (shell prompt), or automatically (AtomicRocketTurtle's Automatic Secondary DNS scripts), or manually with a free GUI (Webmin).

"There are always options. - forgot who said that"

 

[belvin]

Thank you jamesyeeoc. Your information was clear and very helpfull.