I was considering adding 220.127.116.11 to the end of my adapter's list of DNS servers as a backup in case everything fails, when it occurred to me that I don't really know how secondary and tertiary DNS servers are treated.
- Under what conditions is the next DNS server used?
- Will the next server be checked if the name isn't resolved?
- Can I configure my machine to query multiple servers if a name is not resolved?
I'm also worried that by adding a DNS server not on my intranet, I may not be able to resolve local names.
- If the first DNS server fails, how long will the secondary DNS server be used?
- When my machine checks to see if the primary DNS server is up, does it stall my current DNS query?
- How do multiple DNS servers affect performance? If I have four DNS servers on my adapter's list and three of them are dead, will it wait for three timeouts before getting an answer?
I'm not sure if this question is OS specific either. Do different operating systems treat this differently?
My goal is to append 18.104.22.168 to the DNS servers on top of what DHCP hands out with a script. I keep running in to stupid DNS problems where my machines wind up with a bogus/unreachable/simply no DNS server due to errors in DHCP configuration that I have no control over. I'm getting sick of it, but I'm wondering if adding this fail safe would cause more problems than it solves.