phuckedup said:
To do this, i want to mix the nameservers so when it can't find the subdomain on server 1, it will find it on server 2.
I don't entirely understand what you want to do :confused4
Do you want a rule that's set to "whatever isn't hosted on server 1, should automatically be handled by server 2, regardless of that fact whether I told it go to server 2 or not"?
If you want some basic level of redundancy, one way that should work with most hosts is:
yourdomain.com
nameserver 1: ns.server1.com
nameserver 2: ns.server2.com
If you want domain.com,
www.domain.com to be handled by server1, but forums.domain.com to be handled by server 2 for example, you'll need to make sure that ns.server1.com has an A record for domain.com and
www.domain.com pointing to the IP of server1 and an A record for forums.domain.com that points to server 2.
ns.server2.com should have an A record that points to the IP of server 2 for domain.com,
www.domain.com and forums.domain.com.
If server1 is up and running all DNS lookup requests will go through ns.server1.com, so (
www.)domain.com will be handled by it and forums.domain.com will be handled by server2.
If server1 is down, clients will try to contact ns.server1.com but fail so next in line is ns.server2.com which will then serve all three subdomains itself.
Do note that this isn't foolproof since both the visitor's OS and their ISP will cache the DNS lookup. Depending on your host that can expire in 1-24 hour(s). Until the lookup expires from either cache they'll still try to contact server1 regardless on whether it's down or not.
In reverse, if server1 is down and
www.domain.com resolves to the IP of server2, visitors will keep contacting server2 for (
www.)domain.com even if server1 comes back online unless the lookup expires.
The way you'd do it if you wanted real redundancy is to direct all DNS lookup to a server (that's guarenteed to always be there), which will then dynamically keep track of server1's status. If server1 goes down, it redirects to server2, if server1 comes back up, it will redirect back to it without having to worry about cached DNS lookups.