I'm helping a buddy of mine with his network and ran into an unexplainable issue. He has an office, then an underground run of ~100' to his 4 bay garage, then another 100' run from the garage to the house. The office has a wireless Buffalo router, a new Comcast Modem and DLink switch. The garage used to have an old DLink router set in bridge mode acting as a switch and a TP LInk WAP. From there, the cable came out of the DLink and went to the house, where it was plugged into another DLink switch. From that switch we had yet another TP Link WAP for the house and a wired HP printer.
Everything seemed to be working fine, except the speeds at the garage and house were dismal. After some testing, I found that if I plugged the cable directly into the WAP in the garage, I would get normal wireless speeds. It was only when it was plugged into the switch did things get weird. The same with the house. If you plugged driectly into the WAP, you got normal speeds, but plugging the WAP into the switch, I got crappy speeds again.
So, we decided that the switches might be going bad / getting old / whatever, so I had him buy two new switches. I installed the first one in the garage, plugged in the WAP and viola' blazing fast wireless. We head down to the house, plug in the new switch to the wall and nothing. The light on the switch illuminates for a split second, then goes off for about 5 seconds, then illuminates for a split second, then goes off. It's acting like it isn't connected. Here is the weird part, if I plug the WAP into the wall, it connects immediately and I get great speeds, but for some reason the switch won't connect. We thoght the switch might be defective, so we swapped them out and the same thing happens.