Hi,
I need to understand the recursive DNS flow to understand what actually source and destination IP addresses travel over the internet while sending DNS queries to know the response.
Lets say small topology is:-
Client(192.168.10.10)---Primary DNS Server(192.168.20.2)----FW NAT Address (20.20.20.20)----Internet---Root Server (30.30.30.30)
Now Client wants to know the IP address of example.com and sends query to Primary DNS server. Where Primary DNS server does not know the answer and forward that query further with the help of Firewall NAT address to the internet. So what would traffic flow. The very first flow I know is as below:-
Client IP Port DNS IP Port
192.168.10.10--32456---Destination(192.168.20.2)--53
What would be thereafter.
Its like
192.168.20.2--53----->20.20.20.20--34567