[Linux] iptables無法過濾URL問題

假設今天用iptable drop www.google.com

iptable command: 

iptables -I FOEWARD -m string --string “google.com" --algo bm -j DROP

但卻無法擋住(drop)www.google.com ...

此問題要從DNS Query看起,DNS Query有兩種方式:

1. HTTP2.0: DNS Query → TCP handshake → TLS handshake
2. HTTP3.0: DNS Query → QUIC handshake