If you want to test whether or not it's ethernet, buy a cheap CAT 8 cable. The specification is improved overall vs older CATs.
And if it is ethernet, end-game ethernet cable: LINKUP - [GHMT & DSX8000 Certified] Cat8 Ethernet Patch Cable
I use this with my laptop and sometimes upload family pictures on Google drive. This cable is slighty faster than thowaway/cheap CAT 8 cables...don't ask me how, but it's definitely superior. If you buy it, just bend it in to place as it's a bit inflexible. It even comes with a certification paper that gurantees its performance.