一个简单的 sing-box 配置

config.json

{
     "inbounds": [
        {
                "type": "tun",
                "address": [ "172.19.0.1/30" ],
                "auto_route": true,
                "strict_route": false
        }
     ],
     "outbounds": [
        {
                "tag": "proxy",
          // your outbound server, don't change the above line
        },
        {
                "type": "direct",
                "tag": "direct"
        },
        {
                "type": "block",
                "tag": "block"
        },
        {
                "type": "dns",
                "tag": "dns-out"
        }
     ],
     "log": {
        "level": "warn"
     },
     "dns": {
        "servers": [
                {
                        "tag": "google",
                        "address": "tls://8.8.8.8",
                        "detour": "proxy"
                },
                {
                        "tag": "local",
                        "address": "https://223.5.5.5/dns-query",
                        "detour": "direct"
                }
        ],
        "strategy": "ipv4_only",
        "rules": [
                {
                        "outbound": "any",
                        "server": "local"
                },
                {
                        "rule_set": "geosite-geolocation-cn",
                        "server": "local"
                },
                {
                        "type": "logical",
                        "mode": "and",
                        "rules": [
                                {
                                        "rule_set": "geosite-geolocation-!cn",
                                        "invert": true
                                },
                                {
                                        "rule_set": "geoip-cn"
                                }
                        ],
                        "server": "google",
                        "client_subnet": "114.114.114.114/24" // Any China client IP address
                }
        ]
     },
     "route": {
        "final": "proxy",
        "rule_set": [
                {
                        "type": "remote",
                        "tag": "geosite-geolocation-cn",
                        "format": "binary",
                        "url": "https://raw.githubusercontent.com/SagerNet/sing-geosite/rule-set/geosite-geolocation-cn.srs"
                },
                {
                        "type": "remote",
                        "tag": "geosite-geolocation-!cn",
                        "format": "binary",
                        "url": "https://raw.githubusercontent.com/SagerNet/sing-geosite/rule-set/geosite-geolocation-!cn.srs"
                },
                {
                        "type": "remote",
                        "tag": "geoip-cn",
                        "format": "binary",
                        "url": "https://raw.githubusercontent.com/SagerNet/sing-geoip/rule-set/geoip-cn.srs"
                }
        ],
        "rules": [
                {
                        "type": "logical",
                        "mode": "or",
                        "rules": [
                                {
                                        "protocol": "dns"
                                },
                                {
                                        "port": 53
                                }
                        ],
                        "outbound": "dns-out"
                },
                {
                        "geoip": [
                                "private"
                        ],
                        "outbound": "direct"
                },
                {
                        "type": "logical",
                        "mode": "or",
                        "rules": [
                                {
                                        "port": 853
                                },
                                {
                                        "network": "udp",
                                        "port": 443
                                },
                                {
                                        "protocol": "stun"
                                }
                        ],
                        "outbound": "block"
                },
                {
                        "rule_set": [
                                "geoip-cn",
                                "geosite-geolocation-cn"
                        ],
                        "outbound": "direct"
                }
        ],
        "auto_detect_interface": true
     },
     "experimental": {
        "cache_file": {
                "enabled": true,
                "store_rdrc": true
        },
        "clash_api": {
                "default_mode": "Enhanced"
        }
     }
}

保存放到 /etc/sing-box/ 目录下面。gentoo 可以通过 gentoo-zh overlay 安装 sing-box，然后使用 systemctl 启动就可以。
启动之后就会自动代理系统全部流量，然后分流。