I have a BranchA Network on a subnet say 172.16.22.0/24.
BranchA WWW traffice is Nated on ISP Gateway router.
HQ has subnet say 10.2.22.0/23
There are 2 links from BranchA to HQ
1 - Via Internet (access servers with nated address via public IP)
2 - Via a private Link directly to the Server
There is a server in HQ that will be access via PBN Link on Internal IP and via Internet on the Nated public address.
HQ has DNS server and Branch A has DNS server.
The questions is;
I want to Build a redundancy DNS resolution for Users in Branch A accessing the Server in HQ
Now when PBN is UP users in BranchA should have server resolve the server.name.etc to internal server IP HQ
but
When PBN is down, users in BranchA should have Server resolve the server.name.etc to external server IP in HQ
I have tried stub DNS forwarders and Zone Forwarding but when PBN link drops, users accessing server.name.etc still have dns entry as internal IP name.
