This happened once last year too - I remember them saying something about how it shouldn't be possible for both to go down at once haha.

+1 just swapped pi-hole over to google dns all good now

Moved to correct sub-forum.

+1 

I just checked all the 2D nameservers I have listed and here are the results:

202.37.101.1 Ok

202.37.101.2 Ok

202.37.101.3 Not responding

2406:e000::100 Ok

2406:e000::200 Ok

Does anyone have any other addresses?  I can not find a list of them on their web site at the moment.

They're back up now. I'm not aware of any others. 

Just like email,  another reason not to use ISP provided services? 

IcI:

Just like email,  another reason not to use ISP provided services? 

So what's the point of having 2 DNS servers if they aren't fully redundant?

Not sure if the servers were down or if this was isolated to certain parts of the network, didn't notice any issues with the resolvers from an Enterprise connection