How to scan TCP port using NMAP?

As we know that Every computer or device which using internet has unique number known as IP Address. IP Address contain number of TCP and UDP port to do communication. In each IP Address (16 bit) contain 0 to 65535 TCP port and 0 to 65535 UDP port. Every port work on specific service.

Here we do scan on TCP port. TCP port will be use for TCP connections means connections are secure as well as reliable.

For TCP port scan we use -sT command.

here we can see that there are several port available which are open TCP port. This scanning also give information about service of specific port.

Example: 21/tcp Open ftp

21 - Port Number

tcp - Port Type

Open - Status

ftp - Port service and this port use for File Transfer Protocol