Node-RED SNMP Trap Listener

This Node-RED node will bind itself to the configured port and start listening for SNMP Trap packages that meet the filter settings.

One can filter the received data by ip + netmask and/or by a community string.

Forked and modified from https://github.com/ItsEcholot/node-red-contrib-snmp-trap-listener to pass incoming community through payload.

Getting Started

Navigate to the node-red installation directory and add the package via NPM.

cd $HOME/.node-red
npm install node-red-contrib-snmp-trap-listener

Restart node-red and reload your node-red browser window for changes to take effect. Remember to configure the snmp-trap-listener node before you deploy your changes.

Documentation

Input

The snmp-trap-listener doesn't take any input.

Output

The emitted payload object contains an array which contains all received variable bindings in the following format:

{
    oid: "1.3.1",                   //OID path
    typename: "OctetString",        //Typename
    value: [Buffer],                //Contains raw data in a Buffer if String
                                    //or data if Integer
    string_value: "test_value"      //Contains data as a string
}

Options

The node contains the following options:

• Port - Sets the port on which to listen for SNMP traps
• Community - If set every package get's checked if it contains the same community string as set.
  If it doesnt't, the package get's denied and a debug message is emitted.
• IP Filter - If set every package get's checked if its origin matches the IP Filter made from the IP and the mask set.

Sample Output Payload

[
  {
    "oid": "1.3.1.1",
    "typename": "OctetString",
    "value": {
      "type": "Buffer",
      "data": [
        116,
        101,
        115,
        116,
        86,
        97,
        108,
        117,
        101
      ]
    },
    "string_value": "testValue"
  },
  {
    "oid": "1.3.1.1",
    "typename": "Integer",
    "value": 5,
    "string_value": "5"
  }
]

Debugging

Run index.js with node to start the listener in your debugger of choice.

Built with / Dependencies

• snmpjs - SNMP library
• moment - Timestamp format library