The Port 123 is a popular computer network port that is used for both TCP and UDP protocols. Port 123 is used by protocols like NTP but in some cases, some trojans may use this port as it is generally allowed inside enterprise networks. The NTP or Network Time Protocol is simply used to set a date and time-related information via the computer network. The NTP is defined in RFC 5905 .
Check Port 123
We can use different commands and methods in order to check if port 123 is open for Windows and Linux operating systems. The netstat command can be used to check local port 123. For Linux operating systems use the following netstat command.
$ netstat -ulFor Windows operating systems use the following netstat command to check port 123.
$ netstat -aPort 123 Security
As a popular port number, the port123 UDP can be used by different viruses and trojans for communication reasons. So be aware that port 123 can be harmful in some cases if the remote system or local system uses it. Net Controller , Madfind and similar trojans use port 123 for security attacks. But these trojans and viruses generally use TCP 123 in order to make the communication stable.