Performing a basic port scan (nmap -F dl.xamarin.com)
Nmap scan report for dl.xamarin.com (13.65.45.30)
Host is up (0.025s latency).
Not shown: 98 filtered ports
PORT STATE SERVICE
80/tcp open http
443/tcp open https
Nmap done: 1 IP address (1 host up) scanned in 3.09 seconds