This took us some time to figure out… we had a brand new Dell Latitude E6420 over here, and it refused to connect with our LAN when we hooked it up to a Dell PowerConnect 5548 Switch.
- Direct connections between the laptop and the PowerConnect switch were refused: No DHCP lease, no traffic, sometimes Network link was just down
- The laptop could connect to this switch if we used a small switch/hub between the laptop and the Powerconnect Switch
- Direct connections worked if we booted from a live CD (Ubuntu)
- Direct connections did not work on Windows Xp and Windows 7 (fresh installs)
- Network cable was not damaged
- Laptop NIC (Mainboard) has been swapped by Dell, so we made sure this one was not faulty, too
- We experienced the same behaviour with a second brand new Dell Latitude E6420
- Navigate to the Device Manager.
- Open the category of “Network adapters”.
- Right click on the icon for the “Intel(R) 82579LM Gigabit Network Connection” and choose “Properties”.
- Click on the “Advanced” tab and set the Property of “Energy Efficient Ethernet” to “Disabled”.
- Click on the “OK” button to save changes and then close all open windows.
Latitude E6320, Latitude E6420, Latitude E6420 ATG, Latitude E6520, Optiplex 790, Optiplex 990, Dell Precision WorkStation T1600, Dell Precision Mobile WorkStation M4600, Dell Precision Mobile WorkStation M6600
But future systems may have this problems, too… I wonder if Dell is going to update the NIC drivers or the PowerConnect firmware to fix this problem once and for all. IMHO manually switching the EEE option in the Device Manager is not a final solution.
Update: Dell just told me that they are currently working on a new Network Card Driver which should fix the problem. Unfortunately they can’t tell me it’s release date yet.