After enabling the system proxy in the VPN, local test domain names (such as *.test) suddenly can't be accessed?
Wrong move: Add a DIRECT (direct connection) rule in the proxy software.
This is useless! Because once traffic enters the proxy software, it will use public DNS to look up this local domain name. If it can't find the IP, it will immediately report an error and block it.
Correct approach: In the operating system's "Network Settings -> Proxy Bypass List (Bypass)", add *.test (or configure the Bypass bypass list in the proxy software).
Core principle:
Traffic is first received by the operating system.
Bypass (bypass): Traffic never enters the proxy software; the operating system handles it itself and uses local DNS to access directly.
DIRECT (direct connection): Traffic has already entered the proxy software; the proxy software attempts a direct connection, but usually fails at DNS resolution.
I've encountered this problem before and have always been able to solve it, but today is the first time I've fully understood it.