DNS round robbin with failover
I’ve noticed that NS records in DNS also work on a round robbin feature, NS records also alternate.
This implies that you could create a distributed load balancer with failover using only DNS
Server A ip (Multihomed; 126.96.36.199 and 188.8.131.52)
A NS1 184.108.40.206
A NS2 220.127.116.11
A www 18.104.22.168
Server B ip (Multihomed; 22.214.171.124 and 126.96.36.199)
A NS2 188.8.131.52
A NS1 184.108.40.206
A www 220.127.116.11
SERVER.COM delegated with nameservers NS1.SERVER.COM and NS2.SERVER.COM
Now, the A records are not load balanced but the NS records are.
So theoretically, a DNS client, connecting randomly to NS1 or NS2 will be given either 18.104.22.168 or 22.214.171.124 as an IP address, depending
on what nameserver it contacted.
If the DNS on NS1 goes down, then the client will automatically contact NS2. and be given server 2’s IP address. The logic being, that if the DNS
server is down, the webserver probobly is too.
In this case, the A records are not load balanced but the NS records are.
I assume this would not get past ZoneCheck for delegation of some top level domains like .fr, .de or .no, but it might work for a .com