Why do port numbers exist?
A port is simply a channel of communication which is numbered between 1 and 65000. All network devices use them and most have the ability to change them when required. They were originally created to allow multiple programs to use the same IP address.
What is the difference between port number and IP address?
The difference between IP Address and Port Number is that the IP is a numerical label that helps to identify a specific device in the network while the Port Number is a numerical value assigned to a process in the device.
Why do we need IP address and port number?
The IP address is a numerical label assigned to each device connected to a computer network that uses the Internet Protocol for communication. The port number is used so the data is directed to the correct location within this device.
What type of port numbers are always used?
The most commonly used and best-known ports are those numbered 0 to 1023 dedicated for Internet use, but they can extend far higher for specialized purposes. Each port set or range is assigned specialized jobs or functions, and that’s generally all they do.
Which port number can be used to prevent the duplication?
Registered ports—Ports in the range 1024 to 49151 are not assigned or controlled, but can be registered to prevent duplication. Dynamic ports—Ports in the range 49152 to 65535 are not assigned, controlled, or registered. They are used for temporary or private ports.
Do port addresses need to be unique Why or why not why are port addresses shorter than IP addresses?
Port addresses need not be unique as long as each IP address/port address pair uniquely identifies a particular process running on a particular host. Each server uses the well known port number 7, but the IP address, together with the port number of 7, uniquely identify a particular server program on a particular host.
Can two IP addresses use same port?
Yes. Multiple listening TCP sockets, all bound to the same port, can co-exist, provided they are all bound to different local IP addresses. Clients can connect to whichever one they need to.
Why is port 443 open?
If port 443 is open on a computer, that usually means web servers are waiting for a connection from a web browser. You can test whether the port is open by attempting to open an HTTPS connection to the computer using its domain name or IP address.