I want have two master dns servers. Every one of servers has single different external IP. I read about dns server that:
'The most significant caveat to this design is that both masters MUST now be kept in sync and have identical data.'
First question: What does it mean "masters must be kept in sync"?
Second question: Let's say I have at A server dns docker in Arch Linux built few years ago. At B server I have debian based dns docker with different architecture of dirs in bind. Is it possible to have identical data in both servers? How it should be look like? Do we only need identical zones?
EDIT1: I have two proxy servers too. I want to host one website(one domain) on two servers. I want have two independent servers and host websites on them independently.
EDIT2: How should look like dns zone? Is it could be something like below:?
TTL 86400
@ IN SOA (2017121413 10800 604800 10800 )
@ IN NS ns1.example.com.
@ IN NS ns2.example.com.
ns1 IN A IP_server_1
ns2 IN A IP_server_2
@ IN A IP_server_2
www IN A IP_server_2
@ IN A IP_server_1
www IN A IP_server_1