Welcome to the forums.
Sorry to hear you're having trouble. Please take a few moments to review the Forum Rules, conveniently linked at the top of every page in red, and pay particular attention to the section on how to formulate a useful problem report, especially including a detailed description of your hardware, whether you're using Core or Scale, and the specific ethernet chipset used in your system.
You've basically given no one anything to work with, so the responses will tend to be random guesses rather than anything useful.