Performing a basic port scan (nmap -F citibank.co.kr)
Nmap scan report for citibank.co.kr (192.193.81.203)
Host is up (0.14s latency).
Other addresses for citibank.co.kr (not scanned): 192.193.83.203
Not shown: 98 filtered tcp ports (no-response)
PORT STATE SERVICE
80/tcp open http
443/tcp open https
Nmap done: 1 IP address (1 host up) scanned in 4.56 seconds