sing-box tun 模式不定时断流，需要重启

原版 openwrt/immortalwrt sing-box tun 模式不定时断流，症状是无法联网，需要重启后恢复。netstat 显示有大量 CLOSE_WAIT 连接。后来写了个定时脚本去 check ，CLOSE_WAIT 连接数超阀值了重启，改善不少，但偶尔还是会断流。 网上搜了，github issue 里有类似问题，但没找到有效解决办法。

求 V2 大神指导下～

客户端配置参考的是： https://www.right.com.cn/forum/thread-8314833-1-1.html

{
  "log": {
    "disabled": false,
    "level": "debug",
    "timestamp": true
  },
  "experimental": {
    "clash_api": {
      "external_controller": "127.0.0.1:9090",
      "external_ui": "ui",
      "external_ui_download_url": "",
      "external_ui_download_detour": "",
      "secret": "",
      "default_mode": "Rule"
    },
    "cache_file": {
      "enabled": true,
      "path": "cache.db",
      "store_fakeip": true
    }
  },
  "dns": {
    "servers": [
      {
        "tag": "proxydns",
        "address": "tls://8.8.8.8/dns-query",
        "detour": "select"
      },
      {
        "tag": "localdns",
        "address": "h3://223.5.5.5/dns-query",
        "detour": "direct"
      },
      {
        "address": "rcode://refused",
        "tag": "block"
      },
      {
        "tag": "dns_fakeip",
        "address": "fakeip"
      }
    ],
    "rules": [
      {
        "outbound": "any",
        "server": "localdns",
        "disable_cache": true
      },
      {
        "clash_mode": "Global",
        "server": "proxydns"
      },
      {
        "clash_mode": "Direct",
        "server": "localdns"
      },
      {
        "rule_set": "geosite-cn",
        "server": "localdns"
      },
      {
        "rule_set": "geosite-geolocation-!cn",
        "server": "proxydns"
      },
      {
        "rule_set": "geosite-geolocation-!cn",
        "query_type": [
          "A",
          "AAAA"
        ],
        "server": "dns_fakeip"
      }
    ],
    "fakeip": {
      "enabled": true,
      "inet4_range": "198.18.0.0/15",
      "inet6_range": "fc00::/18"
    },
    "independent_cache": true,
    "final": "proxydns"
  },
  "inbounds": [
    {
      "type": "tun",
      "inet4_address": "172.19.0.1/30",
      "inet6_address": "fd00::1/126",
      "auto_route": true,
      "stack": "system",
      "strict_route": false,
      "sniff": true,
      "sniff_override_destination": true,
      "domain_strategy": "prefer_ipv4"
    }
  ],
  "outbounds": [
    {
      "type": "trojan",
      "tag": "trojan-us",
      "server": "XXX.XXX.XXX.XXX",
      "server_port": XXXXX,
      "password": "XXXXXX",
      "tls": {
        "enabled": true,
        "server_name": "XXX.XXX",
        "utls": {
          "enabled": true,
          "fingerprint": "firefox"
        }
      },
      "multiplex": {
        "enabled": true
      }
    },
    {
      "type": "hysteria2",
      "tag": "hy2-us",
      "server": "XXX.XXX.XXX.XXX",
      "server_port": XXXXX,
      "password": "XXXXXX",
      "tls": {
        "enabled": true,
        "server_name": "www.bing.com",
        "insecure": true,
        "alpn": [
          "h3"
        ]
      }
    },
    {
      "tag": "direct",
      "type": "direct"
    },
    {
      "tag": "block",
      "type": "block"
    },
    {
      "tag": "dns-out",
      "type": "dns"
    },
    {
      "tag": "select",
      "type": "selector",
      "default": "auto",
      "outbounds": [
        "auto",
        "trojan-us",
        "hy2-us"
      ]
    },
    {
      "tag": "auto",
      "type": "urltest",
      "outbounds": [
        "trojan-us",
        "hy2-us"
      ],
      "url": "https://www.gstatic.com/generate_204",
      "interval": "1m",
      "tolerance": 50,
      "interrupt_exist_connections": false
    }
  ],
  "route": {
    "rule_set": [
      {
        "tag": "geosite-geolocation-!cn",
        "type": "remote",
        "format": "binary",
        "url": "https://cdn.jsdelivr.net/gh/MetaCubeX/meta-rules-dat@sing/geo/geosite/geolocation-!cn.srs",
        "download_detour": "select",
        "update_interval": "1d"
      },
      {
        "tag": "geosite-cn",
        "type": "remote",
        "format": "binary",
        "url": "https://cdn.jsdelivr.net/gh/MetaCubeX/meta-rules-dat@sing/geo/geosite/geolocation-cn.srs",
        "download_detour": "select",
        "update_interval": "1d"
      },
      {
        "tag": "geoip-cn",
        "type": "remote",
        "format": "binary",
        "url": "https://cdn.jsdelivr.net/gh/MetaCubeX/meta-rules-dat@sing/geo/geoip/cn.srs",
        "download_detour": "select",
        "update_interval": "1d"
      }
    ],
    "auto_detect_interface": true,
    "final": "select",
    "rules": [
      {
        "domain_suffix": [
          "synology.com",
          "plex.tv"
        ],
        "outbound": "direct"
      },
      {
        "outbound": "dns-out",
        "protocol": "dns"
      },
      {
        "clash_mode": "Direct",
        "outbound": "direct"
      },
      {
        "clash_mode": "Global",
        "outbound": "auto"
      },
      {
        "rule_set": "geoip-cn",
        "outbound": "direct"
      },
      {
        "rule_set": "geosite-cn",
        "outbound": "direct"
      },
      {
        "ip_is_private": true,
        "outbound": "direct"
      },
      {
        "rule_set": "geosite-geolocation-!cn",
        "outbound": "auto"
      }
    ]
  },
  "ntp": {
    "enabled": true,
    "server": "ntp.aliyun.com",
    "server_port": 123,
    "interval": "30m",
    "detour": "direct"
  }
}