I'm a Sysadmin and am responsible for our external DNS servers. We're trying to make our DNS more resilient.
We have our own DNS servers (Bind). We have one running on each of our two ISP's.
Their IP's are public IP's on the internet, and one is configured as a master, as one as a slave (this is all working).
The question I have.. when one of our ISP's goes down, we tend to lose DNS completely. From what we can tell, this is because our TLD DNS servers are issuing both nameserver's IP's even though one is down.
How do we get around this?