Bind DNS question

Webmin
1

Hello!

I’m setting up three virtualmin server (master and 2 slaves). My question is I want to configure wich DNS address in network configuration

/etc/sysconfig/network-scripts/ifcfg-eth0

DNS1=127.0.0.1
DNS2=108.61.10.10 #vultr dns
DNS3=1.1.1.1

Here is my questions:

1 - The 127.0.0.1 needs to be the DNS1?

2 - The DNS2 and DNS3 are irrelevant here?

3 - The network configuration in slave zone will be the same as the master?

4 - Vultr offer a DDOS protection, but they alert: “Ensure your server is configured to use 108.61.10.10 for recursive DNS”. In above example I will be able to use the DDOS service? Or I need to put the 108.61.10.10 in DNS1 and 127.0.0.1 in DNS2? Or these change will break the BIND server?

I’m a little bit confused about that…