l2tp转socks5，通过v2ray，tcp协议正常，udp 协议不正常！

[cqfriend]

v2ray 配置

{
  "log": {
   "access": "/var/log/message",
   "error": "/var/log/message",
   "loglevel": "warning"
  },
  "inbounds": [{
    "tag":"tmdl",
      "port": 12345, 
      "protocol": "dokodemo-door",
      "settings": {
	   "network": "tcp,udp",
       "followRedirect": true 
      },
      "sniffing": {
        "enabled": true,
        "destOverride": ["http", "tls"]
      },
	  "streamSettings": {
        "sockopt": {
          "tproxy": "tproxy" 
        }
      },

  "dns": {
    "servers": ["1.1.1.1"	]
  }
	
    }

],

  "outbounds": [{

    "protocol":"socks",
    "settings":{
        "servers":[{
        "address": "x.x.x.x",
        "port": 3000,
		"users": [
                {
                    "user": "user",
                    "pass": "123"
                }
            ]
        }]
    },
    "tag":"socksout1"
},
 {
      "protocol": "dns",
      "tag": "dns-out",
      "settings": {
      "address": "223.5.5.5"
      }
    }
],


  "routing": {
    "domainStrategy": "IPOnDemand",
    "rules":[
	{
        "type": "field",
        "inboundTag": "tmdl",
        "port": 53,
		"network": "udp",
        "outboundTag": "dns-out"
      },
    {
        "type":"field",
        "inboundTag":"tmdl",
        "source":[
            "192.168.18.2"
        ],
        "outboundTag":"socksout1"
    }
	 
    
    ]
  }
}

iptables 配置

iptables -t mangle -N V2RAY
iptables -t mangle -A V2RAY -d x.x.x.x -j RETURN
iptables -t mangle -A V2RAY -d 0.0.0.0/8 -j RETURN
iptables -t mangle -A V2RAY -d 10.0.0.0/8 -j RETURN
iptables -t mangle -A V2RAY -d 127.0.0.0/8 -j RETURN
iptables -t mangle -A V2RAY -d 169.254.0.0/16 -j RETURN
iptables -t mangle -A V2RAY -d 172.16.0.0/12 -j RETURN
iptables -t mangle -A V2RAY -d 192.168.0.0/16 -j RETURN
iptables -t mangle -A V2RAY -d 224.0.0.0/4 -j RETURN
iptables -t mangle -A V2RAY -d 240.0.0.0/4 -j RETURN
iptables -t mangle -A V2RAY -j TPROXY -p tcp --on-port 12345 --tproxy-mark 1
iptables -t mangle -A V2RAY -j TPROXY -p udp --on-port 12345 --tproxy-mark 1

ip route add local default dev lo table 100
ip rule add fwmark 1 lookup 100

iptables -t mangle -A PREROUTING -j V2RAY

其中
192.168.18.2 为l2tp客户端的地址
tcp 访问都正常的，udp 无法转发。
socks5服务端口支持udp转发

[cqfriend]

v2ray日志

[cieyget]

有什么好的解决办法吗？同样的问题