MQTTnet/Source/MQTTnet.Server/appsettings.json

{
    "MQTTnet": {
        /*
         Wildcard Addresses:
          *             - All local IP addresses
          localhost     - Localhost only
          disable       - Skip address assignment
        */
        "Listen": {
            "Enabled": true,
            "IPv4": "localhost",
            "IPv6": "localhost",
            "Port": 1883
        },
        "ListenEncryption": {
            "Enabled": false,
            "IPv4": "localhost",
            "IPv6": "localhost",
            "Port": 8883,
            "CertificatePath": "/absolute/path/to/certificate"
        },
        "CommunicationTimeout": 15, /* In seconds */
        "ConnectionBacklog": 0, /* Set 0 to disable */
        "EnablePersistentSessions": false,
        "MaxPendingMessagesPerClient": 250
    },
    "Logging": {
        "LogLevel": {
            "Default": "Warning"
        }
    },
    "AllowedHosts": "*"
}