The "System Agent" drop-down box in the bottom column of v2rayN has several options, and novices often try them one by one. In fact, the difference between them is just one sentence: Who decides which traffic goes through the proxy?. Once you understand this, it will be clear which one to choose.
1What are the four options?
- Clear system agents: Turn off the system agent and restore direct connection to the computer. Use it when exiting the agent or troubleshooting problems.
- Automatic configuration system agent (PAC): Install a PAC rule script for the system, and this script will determine which websites are proxies and which are directly connected. With the "Bypass Mainland" routing, domestic stations are directly connected, and foreign stations are connected through agents. Most commonly used in daily life.
- Global (set system proxy): Point the entire system proxy to v2rayN, and all software traffic that recognizes the system proxy will go through the proxy (whether it goes through the proxy depends on the routing rules).
- Without changing the system agent: v2rayN only opens ports locally and does not change system settings. Suitable for situations where you want to manually configure an agent for a certain software.
2How to choose between PAC and global
This is the most asked question. Simple conclusion:
- In most cases, choose "Automatic Configuration System Proxy (PAC)" + Routing "Bypass Mainland China". Domestic direct connection does not require detours or traffic consumption, and overseas agents automatically use it to provide the smoothest experience.
- When encountering "A certain external network cannot be opened using PAC", temporarily switch to "Global" and try. The domain names of some sites are not in the PAC list, and the proxy can be forced globally.
A common misunderstanding:"Global" does not mean "all traffic goes through the proxy without thinking." Whether the traffic ultimately goes through the proxy depends on your "routing" settings in the bottom column. The global system only points the system agent to v2rayN, and the routing rules still take effect.
3So what is Tun mode?
The above four are all at the "system proxy" level, relying on software to consciously read proxy settings. And Tun mode It is a lower-level virtual network card solution that can take over Programs that do not even recognize system agents. Use it only when you need global takeover (games, command line tools), just use PAC for daily use. The two are generally not opened at the same time.
4Quick comparison
- Just want to surf the Internet normally: Automatically configure system proxy (PAC) + bypass the mainland.
- An external network cannot be opened: Temporarily cut the whole situation.
- Game/command line requires proxy: Tun mode.
- Don't want to use it anymore: Clear system agents.