It's pre terminated pure copper direct burial cat6 from Amazon. I don't have access to a real tester, but my cisco switch has some built in test capability and I'm not sure I fully understand the results, but it's assessment of the cable length is pretty close and, more importantly, it shows all the pairs are the same as each other. I think that if there was some damage to the cable, it's unlikely that it would affect all the pairs in exactly the same way. I have other weird grounding issues - like 20V between neutral and ground, even though it's a new house and they're properly bonded at the service entry. I had a really old transformer on the street feeding the two buildings and the power company recently replaced it - I was disappointed when this didn't resolve all my issues.