I used to support a small warehouse office that had the most boring network setup possible. A few switches, a firewall, one server closet, nothing fancy.

One week they started getting network drops every night around 10:30pm.

Not full internet down, just random devices losing connection. Shipping terminals would disconnect, one office PC would drop, then everything would come back a few minutes later. Logs showed link flaps on the same switch ports, but nothing obvious.

I checked cables. Replaced a small switch. Checked the wall ports. Everything looked fine.

The weird part was that it never happened during the day. Only at night.

So I stayed late one evening because I wanted to see it happen live. Around 10:25, the cleaning crew came in. Normal stuff. Trash bags, mops, vacuum, all that.

Then I heard a tiny plastic bump from the server closet area.

A little robot floor cleaner had rolled in through the open closet door and was repeatedly trying to fight the cable bundle coming out from under the rack. It would bump the cables, back up, turn, hit them again, and keep doing this like it had a personal grudge against Ethernet.

Every hit was just enough to wiggle a couple already loose patch cables.

Network drops explained.

Apparently someone in facilities had bought the robot a month earlier and set it to run every night. Nobody told IT because, quote, “it’s just cleaning.”

I replaced the loose cables, added proper cable management, and put a small door stopper so the robot couldn’t get into the closet anymore.

Next morning the warehouse manager asked if I found the issue.

I told him yes, the network was being attacked by a Roomba.

He thought I was joking until I showed him the video.