The rule will redirect ONLY matching traffic:
- UDP or TCP
- From the 10.0.0.0/24 network
- To any IPv4 address with a destination port "domain" -- that's port number 53, as defined in /etc/services. Port 53 is the standard destination port number for the Domain Name System.
All of the traffic from 10.0.0.0/24 destined for domain name servers will match and use this redirection. Any other network traffic -- such as traffic destined to HTTP/HTTPS servers -- will not match and will not use this redirection rule.