A question with regards to DNS for my 20 or so websites I support...
I own/manage about 20 domains, each domain has 1-8 subdomains. about 1/2 of the domains are on one dedicated server, the rest on another.
I am trying to plan for the possibility that someday a server will go down, and I need to quickly redirect my DNS to a backup server. To do that now, I would need to manually go into my dns control panel and change the IP in about 30-40 places.
Is it possible (and is it a good idea if it is possible), to define a single DNS record as "MyMainServer" and give it the actual IP address, and then for every other DNS record, instead of keying in the IP address, I give it a domain name? Will this resolve properly, and if so, is there any performance impact that matters? (my sites are relatively low traffic).
My thought is that then if a server goes down, I only have to point one "main" dns record, and everthing else will flow from that.
Thanks in advance.