Setting up "Server Down" notice on second box?

I have 2 dedicated servers, and I'm looking into setting up ServerB to show a temporary "We're Down" page when ServerA goes down.

Both servers are at different hosts/different data centers. Both use CPanel/WHM/BIND 9. I plan to use CPanel's DNS clustering to keep NS2 and NS1 synched.

ServerA contains NS1.Host.com.
ServerB contains NS2.Host.com.

Process if ServerA goes down (taking the primary nameserver with it!):
1. When I notice the main server is down or decide to take it down I will manually update all my domain's zone records at NS2.Host.com to direct traffic to the working IP (and temporary webpage).
2. When ServerA/NS1 come back up NS2 automatically requests a zone transfer from NS1, overwriting the manual changes made in Step 1.

Is that correct?

What kind of TTL values should I permanently use to ensure this works in a timely fashion? I don't want to set them so low that the server sees a lot of extra DNS traffic. I would be happy if everybody in the world saw the Server Down page within 5 minutes of Step 1 above being performed. What kind of issues would prevent this from working? TIA!

 

 

 

 

Top