TCP in Node auto respons [72,67,202,1,1,...]

[bjdaijun]

Current Behavior

And if I connect to tcp in node, It‘s will send back some bytes to client. But these data not from my configs.

Expected Behavior

Client do not receive any data when not send data by hand.

Steps To Reproduce

use this config, and node debug68 will receive these bytes repeatedly.

Example flow

[
    {
        "id": "19d8c6fadea93ef9",
        "type": "tab",
        "label": "tcp-test",
        "disabled": false,
        "info": "",
        "env": []
    },
    {
        "id": "1787daf384b3888d",
        "type": "tcp in",
        "z": "19d8c6fadea93ef9",
        "name": "",
        "server": "server",
        "host": "",
        "port": "28001",
        "datamode": "stream",
        "datatype": "buffer",
        "newline": "",
        "topic": "",
        "trim": false,
        "base64": false,
        "tls": "",
        "x": 240,
        "y": 160,
        "wires": [
            [
                "741ee8031febd4d5"
            ]
        ]
    },
    {
        "id": "ace10560e9081352",
        "type": "debug",
        "z": "19d8c6fadea93ef9",
        "name": "debug 67",
        "active": true,
        "tosidebar": true,
        "console": false,
        "tostatus": false,
        "complete": "payload",
        "targetType": "msg",
        "statusVal": "",
        "statusType": "auto",
        "x": 420,
        "y": 160,
        "wires": []
    },
    {
        "id": "566014e0c80e8a46",
        "type": "tcp out",
        "z": "19d8c6fadea93ef9",
        "name": "",
        "host": "",
        "port": "",
        "beserver": "reply",
        "base64": true,
        "end": false,
        "tls": "",
        "x": 510,
        "y": 260,
        "wires": []
    },
    {
        "id": "741ee8031febd4d5",
        "type": "function",
        "z": "19d8c6fadea93ef9",
        "name": "function 21",
        "func": "",
        "outputs": 1,
        "noerr": 0,
        "initialize": "",
        "finalize": "",
        "libs": [],
        "x": 330,
        "y": 240,
        "wires": [
            [
                "566014e0c80e8a46"
            ]
        ]
    },
    {
        "id": "540233ccc27276ee",
        "type": "tcp in",
        "z": "19d8c6fadea93ef9",
        "name": "",
        "server": "client",
        "host": "iot.mapchang.com",
        "port": "28001",
        "datamode": "stream",
        "datatype": "buffer",
        "newline": "",
        "topic": "",
        "trim": false,
        "base64": false,
        "tls": "",
        "x": 280,
        "y": 380,
        "wires": [
            [
                "ccaa2e6ab665534b"
            ]
        ]
    },
    {
        "id": "ccaa2e6ab665534b",
        "type": "debug",
        "z": "19d8c6fadea93ef9",
        "name": "debug 68",
        "active": true,
        "tosidebar": true,
        "console": false,
        "tostatus": false,
        "complete": "false",
        "statusVal": "",
        "statusType": "auto",
        "x": 560,
        "y": 380,
        "wires": []
    }
]

Environment

• Node-RED version: 3.0.2
• Node.js version:
• npm version:
• Platform/OS: ubuntu
• Browser: chrome

[Steve-Mcl]

And if I connect to tcp in node, It‘s will send back some bytes to client. But these data not from my configs.

Whatever device is on the end of iot.mapchang.com:28001, it is clearly sending this data:

Therefore the TCP node is working as expected.

If you need help using node-red, please head to the forum or slack as was displayed when you raised this issue.
This GitHub issue board is intended for reporting bugs.

Thanks, Steve.

[Steve-Mcl]

Closing issue. Please re-open or comment if you still believe this to be a Node-RED problem.

[bjdaijun]

Closing issue. Please re-open or comment if you still believe this to be a Node-RED problem.

Thank you for your reply. But I still can't got the point. As you see, The node TCP:28001 IS the device that the next node tcp:iot.mapchant.com:28001 (same as tcp:localhost:28001) ,connected to. And the data is send out by the tcp in node (TCP:28001) . But as you see, The Node TCP:28001 send nothing in the function node. But the Node(tcp:iot.mapchang.com:28001) received these data.

So why TCP:28001 send these data internally?

[hardillb]

But the tcp node that is only connected to the debug node is NOT connecting to the tcp-in -> function -> tcp-out flow. This can be seen because there is not "connected 1" status under the tcp-in node.

This means that iot.mapchang.com is not resolving to the machine that Node-RED is running on. So what ever is listening on port 28001 on that machine is sending the data, not Node-RED.

If you change the hostname in the bottom tcp node to localhost you should see the connection and no data being sent

[bjdaijun]

It turns out that in other flow ,there is a tcp-out-response node ,timerly activated and it send that data.
Like these

After remove it, all tcp nodes return clean status.

Thanks for help.