Suggest we use iftop instead of iptraf to identify DDoS

Reference: https://www.slashroot.in/linux-iptraf-and-iftop-monitor-and-analyse-network-traffic-and-bandwidth

Usage:
iftop -i INTERFACE
Example:
iftop -i eth1

The iftop automatically sorts out those network connections occupying excessive bandwidth from the top to the bottom.

The shortcut, "p", helps show the details regarding the source port and destination port for each connection.

The last three columns on the right represent the bandwidth usage for the last 2, 10, and 40 seconds.

Finally, the shortcut, "q", can help exit the program.