In the training and testing dataset, values for most of the numerical columns like duration, src_bytes etc.. are negative. What does that signify ? How duration and bytes could be negative ?
It is normalized dataset and we are using below formula to normalize it, due to which values are negative
normalized = (featurei − μi) / σi
Here, "μ" is Mean and "σ" is Standard Deviation
Please go through below post for more details. It is duplicate question.