During the recent partial outage of Cloudflare's network[1] multiple other DNS providers stopped working, because they were all using Cloudflare's DNS Firewall[2].
The affected services included:
– DigitalOcean DNS
– Linode DNS
– DNSimple DNS
It would be good to know any DNS providers with anti-DDoS protection that won't go down with Cloudflare's network.
[1] https://news.ycombinator.com/item?id=31820635
[2] https://www.cloudflare.com/dns/dns-firewall/