At my previous job, I worked for a university as a network engineer. It was a large campus with lots of agriculture. Because of some of the distances between buildings and the nature of the “farm” on the south side of campus, fiber was not run everywhere.
This is the story of one such building that was provided with a point-to-point wireless link. The shot was just over a mile in distance. Everything worked as expected, and they really only had issues on rainy days.
One bright sunny day, we got a ticket that the Internet was out at the farm building. We went out there, and everything looked fine. We left.
A few days later, the same thing. Okay, odd.
A couple of weeks later, we got the same report. We thought maybe foliage from a nearby tree was causing issues; it was springtime and the link had been installed during winter. So, we trimmed the trees.
But we were still getting reports of outages. We realigned the access points. I didn’t help. What gives?
One day in late summer, some coworkers were out there and noticed a very large bull lying on top of a hill — the same hill that the wireless link shot over.
LIGHTBULB!
They asked about the bull and were told that was his favorite place to lie down. Face-palm.
They raised the access points higher in the air, and the problem went away. A dang cow was blocking the wireless signal!