Forget about power settings, BIOS, event log, etc. Waste of time.
Go to Device Manager, Network adapters, Realtek USB GbE Family Controller. You'll notice the driver is developed by Realtek, right-click, select Uninstall, and check the box that says delete files from disk.
Give it a few seconds to recompose, then Action, scan for hardware changes. The Realtek USB GbE Family Controller will appear again. Big difference, however, the driver is from Microsoft (right-click, Properties).
As long as the driver is from Microsoft, you will not lose Ethernet at the dock after a power save event.
How do you keep it that way? Well, two pesky pieces of software that came with your 5410 are determined to give Realtek another chance. So here's what you need to do:
- In Dell Command | Update, go to the cog on the upper right corner, Update filter, Device Category, and uncheck Audio and Network and Bluetooth. Click OK. That comes with the understanding that you will have to update drivers manually for these categories of course.
But you are not done, and for weeks I kept wondering what else could be covertly updating a driver I explicitly filtered out. Well, that is
- SupportAssist. Open it and click the cog on the upper right corner, choose Settings, Automate scans and optimizations, and uncheck Scan your system and drivers at. So essentially, do not do any unauthorized updates to my computer. Yes, again that means you do some driver updating manually. But again, no automated piece of half-thought software is going to bypass the driver filters you explicitly set to omit.
OK, so with that my WD Ethernet works and will continue to work after a power save event.