I am using nmap to scan open ports of a device (Android smartphone), and nmap returns me that all 1000 scanned ports are closed. Right.
But in the same time I can ping the device. I thought that pinging a device would send a ICMP "echo" message to it, which is using port 7 if I am good.
So, two questions : Why does nmap say that all ports are closed (meaning that the remote computer rejected my connection attempt with a RST packet Filtered), if I can ping on port 7 ? Why does nmap only scan 1000 ports and not 65K ?