There are two types of ports
Software port: It is a piece of software in a machine used to communicate with remote application.
Hardware port: It is a physical peripheral in a machine used to connect systems and devices physically.
The combination of IP address and software port is known as socket number.
The port numbers vary from 0 to 65535(2 power 16=65535).Default ports or Well known ports range from 0 to 1023.
To view all the default port in Linux machine -> $ less /etc/services
Nmap(Network mapper), important monitoring tool used to scan open ports in local and remote machine.Nmap service can be installed in windows,Linux and solaris.
To install nmap command in Linux -> # yum install nmap
Command to scan for open ports in a machine(remote/local)
# nmap hostname
Command to check whether a particular port is open or not
# namp -p port_number hostname
Command to scan for entire network-ID/subnet mask
# namp IP-address/subnetmask
Command to check the protocol supported by the remote machine for communication
# nmap -so hostname
Command to scan for operating system details(remoet/local) with uptime
# nmap -o hostname
Software port: It is a piece of software in a machine used to communicate with remote application.
Hardware port: It is a physical peripheral in a machine used to connect systems and devices physically.
The combination of IP address and software port is known as socket number.
The port numbers vary from 0 to 65535(2 power 16=65535).Default ports or Well known ports range from 0 to 1023.
To view all the default port in Linux machine -> $ less /etc/services
Nmap(Network mapper), important monitoring tool used to scan open ports in local and remote machine.Nmap service can be installed in windows,Linux and solaris.
To install nmap command in Linux -> # yum install nmap
Command to scan for open ports in a machine(remote/local)
# nmap hostname
Command to check whether a particular port is open or not
# namp -p port_number hostname
Command to scan for entire network-ID/subnet mask
# namp IP-address/subnetmask
Command to check the protocol supported by the remote machine for communication
# nmap -so hostname
Command to scan for operating system details(remoet/local) with uptime
# nmap -o hostname
