Slow internet speed over Ethernet

Question

For unknown reason the internet over wired connection is extremely slow.

Here's the setup: Cable modem -> Router (Netgear R7000, latest firmware) -> PCs; laptops, etc.

At some point all internet speeds via wired connections to routers dropped down dramatically. I performed the following tests:

• Internet Download speed over WiFi = 100 Mbit/s
• Internet Download speed over Ethernet = 0.1 Mbit/s
• LAN file transfer Ethernet to Ethernet = 700 Mbit/s
• LAN file transfer WiFi to Ethernet = 300 Mbit/s

I also tested it while only one PC is connected to ensure that nothing is choking the network.

The measurements above are consistent for all 3 PCs. I measured download speed over Ethernet on one of the laptops in another LAN, and it achieved max DL speed (100 Mbit/s). So I'm quite positive that PCs are not the problem.

I suspected that router's internal Ethernet switch might be failing, but high speed internal transfer speeds show that it's OK. Fast internet speeds over WiFi show that modem & internet port are OK as well.

Seems like the only route that is slow is "internet if accessed via wired connection"

Anyone have any insight on what might be causing that, and how to fix it?

Answer 1

It sounds like the part of the router bridging the LAN ports to the virtual LAN port on the motherboard is faulty. I guess this could be a hardware thing, but I imagine firmware issue is more likely. If the router is under warranty I'd return it, otherwise I'd consider flashing DD-wrt on it to see if that fixes it.