Network device disconnects LAN connection and limits speed to 100mbps without obvious cause
Network device disconnects LAN connection and limits speed to 100mbps without obvious cause
I have an Asus RT-AX58U linked to my ISP modem, which operates in bridge mode. Upstairs, three devices are connected, while the fourth port links to an Ethernet cable that descends to the basement and joins a Netgear GS308v2 8-port gigabit switch. This switch interfaces with several devices outside the room and another Ethernet cable connects to a 16-port D-Link DGS-1016A switch on the opposite side of the room, where my desk is located. The D-Link connects to my computer, work laptop, two QNAP servers, printer, another computer, a Mac Mini running Home Assistant, and an extra Ethernet cable that remains mostly unplugged. The port on the Asus router that leads to the basement frequently drops from gigabit to 100Mbps without clear cause. If I disconnect the cable from upstairs and plug it back in, speed returns to gigabit. It drops again when I unplug the cable from the Netgear switch and reconnect it. At this moment, only the Netgear switch, D-Link switch, my computer, and work laptop are active. All other devices are absent. Rebooting the D-Link switch didn’t resolve it; disconnecting the cable from the Netgear to the D-Link didn’t help. But unplugging the router port restores normal speed. It appears there’s no obvious explanation for this behavior. All cables are Cat 6 or higher. Upstairs, the cable runs from the router to a keystone jack I installed in the wall. That connects via a Cat7 cable to a keystone jack in the basement ceiling. From there, a Cat6 cable reaches the Netgear. I replaced the Netgear switch with another model and still faced the issue. I tested various ports on the Asus router, but the same problem persists. The only non-gigabit device in the basement is the Xbox 360, which is usually off and not connected to the switch at the moment. Since it isn’t powered on, it shouldn’t affect the connection. Occasionally the port remains at gigabit all day, yet it frequently drops to 100Mbps. What’s the most effective way to diagnose and fix this? The port has experienced three drops in the past half-hour. I swapped cables in ports 2 and 4 to observe how long port 2 stays operational. Ports 1 and 3 remain yellow, indicating they aren’t gigabit devices.
The connection was terrible, barely reaching 80mbps even on a fast gig internet plan. It was a total waste of money for a new cable that failed after just a couple months.
I'll look into it more closely. The cables along the entire path from the router to the keystones and switch are fairly recent. The ones connecting the router to the keystone and the wall between upstairs keystones and the basement are only a few years old. After testing by connecting the cable from port to port 4 and then to port 2, they stayed active. Once port two reaches 100mbps, I'll replace the cable at the first switch to check for issues.
It seems the issue came from the Cat 6 cable connecting your router to the basement jack. I replaced it with a flat Cat7 cable I had extra that weekend, and performance stayed solid at 100mbps. The new cable appears to be in good condition.
Completely, as I mentioned it happened before. No sharp bends and nothing like that so far; the cable just stopped working without any reason.