Explain how you would train a machine learning model to detect a specific type of DDoS attack (e.g., SYN flood) in Mininet.

First, you'd need to simulate the SYN flood attack in Mininet, generating a large number of SYN packets to a target host. Then, you'd collect network traffic data (features) during both normal network operation and the SYN flood attack. This data would be labeled as either 'normal' or 'SYN flood'. Finally, you'd train a chosen machine learning algorithm (e.g., SVM) on this labeled dataset to learn the distinguishing characteristics of the SYN flood attack.