Hy everyone, I have a PiHole instance running on my home server, and I changed my router (Fritz box) DNS in order to use my PiHole. Everything runs great.
I was wondering if I can put another DNS provider on my “alternative DNS server” in my router, in order to have a fallback alternative in case my server is down, or if I should avoid it.
I’m asking this because I don’t know if the request will be handled in parallel between the two DNS provider (that would make my PiHole useless) or not. Thank you.
There’s no RFC that specifies that a specific order is applied to DNS servers.
RFC 2182 details the operation and functionality of secondary DNS servers. Which defines/influences how resolvers behave with multiple DNS servers.
That RFC is about DNS servers in the context of DNS zones in domain names. Not for a DNS client running DNS queries like an operating system. And the RFC is very clear about this:
For your Windows, Linux whatever machine “there are simply multiple DNS servers”.
It doesn’t. As I said in another comment “most operating systems will just load balance or opportunistically pick between the two”, and there’s the relevant part from the RFC: