using System;

using System.Text.Json;

using System.Collections.Generic;

using System.Text.Json.Serialization;

using System.Linq;

//using Newtonsoft.Json;

public class Program

{

    public static void Main()

    {

        string json = @"{

   ""meta_data"": {

       ""name"": ""myname""

   },

   ""1122413f-2887-4789-a112-31d003f2703a"": {

       ""ipadd"": ""1.1.1.1"",

       ""host"": ""host""

   },

   ""4432313f-2887-4789-a222-31d41231233a"": {

       ""ipadd"": ""1.2.1.1"",

       ""host"": ""h3st""

   }

}";

        RootObject root = JsonSerializer.Deserialize<RootObject>(json);

        Console.WriteLine(JsonSerializer.Serialize(root.Devices, new JsonSerializerOptions { WriteIndented = true }));

    }

}

​

public class RootObject

{

    [JsonPropertyName("meta_data")]

    public Metadata Metadata { get; set; }

​

    [JsonExtensionData]

    public Dictionary<string, JsonElement> Extension { get; set; }

    [JsonIgnore]

    public Dictionary<Guid, DeviceInfo> Devices 

    { 

        get

        {

            return Extension.ToDictionary(x => Guid.Parse(x.Key), v => JsonSerializer.Deserialize<DeviceInfo>(JsonSerializer.Serialize(v.Value)));

        }

    }

}

​

public class DeviceInfo

{

    [JsonPropertyName("ipadd")]

    public string IpAdd { get; set; }

    [JsonPropertyName("host")]

    public string Host { get; set; }

}

​

public class Metadata 

{

    public string Name { get; set; }

}