Simple things first:
1. Is the ethernet/patch cable plugged in?
2. If it is a wireless problem, go to system preferences, click on Network to see if you have an IP# that does not start with these first 3 numbers: 192 or 169.
3. Have you changed your password for your computer or Clemson network recently?
4. Open a browser- if it says Net Registration, you need to re-register your computer. This happens at least once a year!
5. Can you get an IP# where you live, but not on campus? Have you changed anything recently?
After you have checked all these, see someone for help.