windows PE/RE and docking stations - access to Ethernet

@jphughan 

@eslonim  Well the security warnings are justified, because enabling those options means that Thunderbolt devices connected at boot time get to bypass some normal Thunderbolt port security policies.  If that's a point of concern, then you might want to enable those options only when you actually need the dock to be available in a WinPE/RE environment, although that of course is more of a hassle.  If that doesn't fix it though, what WinRE kernel is your bootable environment using?  You might need a newer kernel, and in fact a newer kernel MIGHT allow you to use the dock properly without needing to enable the boot options.  The reason I say that is that the WD19TB supports Kernel DMA Protection, as does the XPS 15 9500.  If the OS environment supports it as well, then it allows Thunderbolt devices to be used without the standard user authorization prompt because Kernel DMA Protection includes some native protection mechanisms of its own.  Without Kernel DMA Protection, Thunderbolt devices have to be authorized by the user when they're attached.  That can be done within full Windows, but not to my knowledge in WinPE/RE -- which is why the boot options were created in order to allow devices connected at boot to be usable without first prompting for user authorization as would normally be required.  But a sufficiently new WinPE/RE kernel might actually support Kernel DMA Protection, in which case you would be able to use the WD19TB without having to "lower shields" by enabling those boot options.  But again, I'm not 100% sure about that since I haven't looked into it.

@jphughan 

Yep, that did it (also the ethernet driver I put in the WinRE 10 release 2004 64 bit. Thanks

(It was built by Macrium Reflect backup software).

Now I have gigabit ethernet access, which will make any restore necessary more feasible than over WiFi

@eslonim  Excellent!  You should have said you were using Reflect.  I'm a big fan of that product and am quite active over on the Macrium forums as well, under the same username.  Best of luck!