1) Make sure you have internet connection.
2) Make sure you are using the correct host name.
For cs457 students: npu8.npu.edu
For cs540, and cs547: npu9.npu.edu
CS230, CS385, and CS515 students use: npu1.npu.edu
For all EE courses: npu29.npu.edu
3) Connection type should be set to SSH, and the port number should be set to 22.
4) If problem still persists: contact the front desk (rm 211).