Hot take: just learned CAT5e is only rated for 328 feet, and I've been running way past that for years
So I pulled up the spec sheet on a box of cable I grabbed off the van and it says 100 meters max, which is 328 feet. I sat there doing the math on a run I did out to a shop building in Fresno that had to be pushing 400 feet, and sure enough the customer was complaining about packet loss. The signal degrades way faster than I thought past that number, which explains a bunch of callbacks I always blamed on the router. Anyone got a solid extender or switch setup they trust for long runs, or do you just tell the customer to suck it up and trench a new line?