Remote port refers to the port number of the receiving host in network communication, in order to distinguish different applications. In the computer network, when the sender and the receiver communicate, in addition to the IP address, they also need to specify the port number to identify the operation of the application. Remote port numbers usually correspond to local port numbers, which together form a network connection.

The purpose of using remote port numbers is to ensure that packets can be delivered to the target host and target application correctly. Each port number corresponds to a different application. If the correct port number is not specified, it is impossible to establish a connection with the target application and transmit data. Therefore, the use of remote port numbers is very important in network communication.

There are many ways to check the remote port number, such as using the command line tools that come with Windows system (such as netstat command) or using some special network monitoring tools (such as Wireshark). Usually, we will use the port scanning tool to scan the port of the remote host to determine the remote port number. However, it should be noted that unauthorized port scanning is illegal and should be used in legal occasions.