Container Docker cannot access LDAP server

Question

I have an application that needs to access an LDAP (Active Directory) server and running the application locally is working normally, however when running the application inside a Docker container it cannot access the Active Directory server. When I run a ping inside the container the LDAP server is reached.

This is the method that connects to Active Directory

        /// <summary>
        /// Construtor da classe
        /// </summary>
        /// <param name="configuration">Parâmetro de configuração</param>
        public ActiveDirectoryClient(IConfiguration configuration, ILogger<ActiveDirectoryClient> logger)
        {
            _logger = logger;
            _configuration = configuration;
            _domain = _configuration["LDAPAdress"];
        }

        /// <summary>
        /// Tenta conectar com o ActiveDirectory até uma quantidade de vezes e um intervalo de tempo fornecido em segundos
        /// </summary>
        /// <param name="attemps">Número de tentativas</param>
        /// <param name="retryInterval">Intervalo de tempo entre as tentativas em segundos</param>
        /// <returns>Retorna o contexto do Active Directory</returns>
        /// <exception cref="CustomException">Lançada quando não é possível se conectar com o ActiveDiretory</exception>
        private PrincipalContext TryConnectActiveDirectory(int attemps, double retryInterval)
        {
            while (attemps > 0)
            {
                _context = null;
                var isRetry = false;


                _logger.LogCritical(_domain);
                try
                {
                    _context = new PrincipalContext(ContextType.Domain, _domain);
                }
                catch (Exception)
                {
                    isRetry = true;
                    attemps--;
                    Thread.Sleep(TimeSpan.FromSeconds(retryInterval));
                }

                if (isRetry || _context.Container == null)
                {
                    attemps--;
                    Thread.Sleep(TimeSpan.FromSeconds(retryInterval));
                }
            }

            _logger.LogCritical(_domain);

            if (_context == null)
            {
                throw new CustomException(HttpStatusCode.ServiceUnavailable, "Não foi possível conectar-se com o servidor");
            }

            return _context;
        }

This is the file with the settings for the project

{
  "LDAPAdress": "10.10.2.1",
  "Logging": {
    "LogLevel": {
      "Default": "Warning"
    }
  },
  "AllowedHosts": "*"
}

I am running the image built on port 60331 which is mapped to port 80. It is working because it has access to Swagger

I ran a tcpdump -i eth0 port 389 to list only the requests that went to ldap server, but I had no results, but if I run the application locally I can get the information.

Could you help me?