Do you have no link layer connection or is this a case of not passing traffic? Are any messages being logged that indicate an error? What OS are you using?
I do not know why you cannot get a connection, but here are a few things you could look at to help troubleshoot:
- Upgrade to the latest driver. Some driver updates do have bug fixes for direct attach cable issues.
- Try a totally different cable model and length in case there is some issue that shows up with the particular model and length you are using.
- You might also check the way you have the cable installed. Some cables might not work right if your bend radius is to great.
Mark H