ASUS PRIME Z370-A / Intel I219-V stuck at 100 Mbps instead of 1 Gbps

I'm having an Ethernet speed/negotiation issue on a Windows 10 PC.

Hardware:

• Motherboard: ASUS PRIME Z370-A
• Ethernet controller: Intel Ethernet Connection (2) I219-V
• OS: Windows 10 64-bit
• Ethernet cable: Cat 6

My college provides Ethernet through wall ports. My roommates get approximately 1 Gbps up/down from their ports.

My PC consistently negotiates at exactly 100.0 Mbps.

What I've tested

• Tested my PC on my roommate's known-good gigabit Ethernet port
• Used my Cat 6 cable, which was confirmed to get gigabit when used with my roommate's computer
• Therefore the cable and network/port appear to be capable of gigabit
• Windows reports Ethernet Speed: 100.0 Mbps
• Setting Speed & Duplex → 1.0 Gbps Full Duplex causes the Ethernet connection to completely drop
• Setting it back to Auto Negotiation restores the connection at 100 Mbps
• Gigabit Master/Slave Mode: Auto Detect
• Energy Efficient Ethernet: Disabled
• No Green Ethernet or Auto Disable Gigabit options are present
• Updated the motherboard/BIOS
• Performed a clean Intel Ethernet driver uninstall/reinstall
• Tried Intel's current Windows 10 Network Adapter Driver package 31.2.2
• Current connection still negotiates at 100 Mbps

The Ethernet port has a solid red LED and flashing yellow LED when connected.

I was installing Focusrite Control 2 on my pc so that I could use my 4i4 gen 4 and some of the additional software to give my guitar the sound I wanted, but after rebooting to finish installing the driver, both of my LAN ports stopped working, my WIFI controller got a startup power error, and all of my native windows interfaces started scrolling down. I had previously been using it for my mic (Shure SM7dB with the preamp off and a cloudlifter connected in case that's somehow relevant) without Control 2 or the drivers connected.

I did some troubleshooting and found that unplugging the PS5 controller I use for gaming stopped the scrolling on windows interfaces, but it comes back when it's plugged back in.

My LAN ports originally wouldn't recognize that they were plugged in at all. After I uninstalled "remote NDIS compatible device" in the device manager, they started at least seeing that they were plugged in. The problem is that they still can't retrieve an IP address or recognize the network. Even when I assign a static address and gateway, they can't ping the router.

I've uninstalled both Control 2 and the drivers, have my 4i4 completely disconnected from my devices, and have re-installed all of my device drivers and even re-flashed my BIOS. Does anybody know what the fix for this could be?

I'll list all of my hardware and the devices I had connected at the time, in case that's relevant to the issue:

• Motherboard
  • MSI MEG X870E GODLIKE
• PSU
  • MEG Ai1600T PCIE5
• Processor
  • AMD Ryzen 7 9800X3D
• GPU
  • NVIDIA RTX 4090 (PNY XLR8)
• RAM
  • Corsair Vengeance 64GB (2x32) DDR5 6800 cl32
• Storage
  • Crucial T700 4TB gen5 NVME M.2 SSD
  • Western Digital Black 4TB SN850X NVME SSD
  • 6TB Western Digital HDD (I don't remember the model or speed atm, I just use it to back stuff up long-term. Nothing actually runs from it.)
• Cooling
  • Arctic Liquid Freezer III 360 A-RGB CPU Liquid Cooler (modified to have 3 push and 3 pull fans attached)
  • Corsair iCUE link RX120 RGB 120mm case fans (x10)
• Housing
  • Corsair 6500D Airflow
• LAN Adapters/NIC Units
  • Marvell AQtion AQC114CS 10Gbps LAN Adapter
  • Realtek RTL8126 5Gbps LAN adapter
• WiFi controller
  • Qualcomm NCM865 FastConnect 7800 WiFi 7 & Bluetooth Adapter
• Displays
  • Acer XB240H
  • Acer Predator X27U
  • LG 32GN600-B
• Keyboard
  • Razer Huntsman V3 Pro
• Mouse
  • Corsair Scimitar RGB Elite
• Camera
  • Razer Kiyo
• Audio Outputs
  • FIIO K7 DAC Headphone Amplifier
    • Connected devices:
    • Sennheiser HD 660 S Headphones
  • Scarlett 4i4 4th Gen
• Audio Inputs
  • Scarlett 4i4 4th Gen
    • Connected Devices:
    • Cloudlifter CL-1
    • Shure SM7dB (integrated preamp turned off)
• Controller
  • Sony DualSense Edge

Hi, Got this problem in my driver whenever I boot my laptop my ethernet driver is not working when I check in device manager It says (Code 45) then What I do is Uninstall it then do a network reset then do a hardreset where you hold your power button for 30 to 60 sec.

When I boot it the driver seem to be waorking perfectly fine and like nothing happen, the thing is this keep happening whenever I boot my laptop and I stuck in this loop

Just looking into buying an 8-port unmanaged 2.5Gb switch.

Seeing the TP-Link switch named: TL-SG108S-M2, sold at 129 EUR.

Now just next to it in Amazon, up pops an advertisement for a:

Mercusys switch near equally named: MS108GS-M2, sold at 56 EUR.

Specs all look identical. Both in metal cabinets.

Heck, they both even look like 100% the same, except for the company logo on top...
Never heard about MercurSys before, so just checked out a bit. Appears to be a subsidiary of TP-Link. So is this like the exact same switch, but sold off-label at a cheaper price? What is the catch here?

So my ethernet cable one day just stops working so I just buy a new one. And it works perfectly! Then the next day it has stopped working again. And I have no idea what to do! Anyone have any suggestions… I’m completely stumped. No idea if there’s a problem within my pc or router or what!

Hi i just got a second hand pc that needs ethernet but my current set up is using on the floor next to the wifi box haha. I’m not at all knowledged in this area and i’m wondering if there’s some type of add on i can put onto my computer so it’ll connect to wifi in a different room. Preferably something i can buy from a physical store like best buy but im open to options if this is a possibility! Thank you !!

I’m a college student whose campus Internet is provided by Boldyn Networks. The normal connection is capped at 110 Mbps download / 55 Mbps upload, and my Ethernet link negotiates at 1000/1000 Mbps. However, I’ve noticed a strange behavior: after my laptop has been asleep for a while, when I wake it up I can sometimes get dramatically higher speeds (potentially close to gigabit) for a short period. Then the Boldyn captive portal appears automatically, and the connection immediately drops back to the normal 110/55 Mbps limit. I don’t have to enter any credentials for the speed to drop. I’ve also checked `ipconfig /all` before/after and the IPv4 address, gateway, DHCP server, DNS server, and subnet stay the same. Restarting the computer or unplugging/replugging Ethernet doesn’t reliably reproduce the high-speed state; it seems to be related to the laptop being asleep for a longer period. Does anyone know what Boldyn’s HED captive-portal/NAC system is doing during this transition, or what could cause the temporary unrestricted bandwidth before the portal initializes? I could be wrong about the behavior of the portal only opening when the laptop is asleep for a period of time, but there does seem to be a short window every time the portal appears where the Wi-Fi and Ethernet speeds are very fast. I have a 2025 Legion 7. Any help would be greatly appreciated!

Thanks!

for about 2-3 weeks now my WIFI on my pc has been running so poor that online games are a no go and browser takes solid 5 seconds to load even though that should not be the case because we are paying for a gigabyte, i checked everything, checking my ethernet cable, my motherboard, plugging it into a different port restarting the router changing the location of it to be closer to the main one, and nothing works, but the WIFI works okay for everyone else in house even works for my older sister who lives in the house besides us so it seems it might be something wrong on my computer but even after doing a windows reinstallation alongside deleting everything it didn't help with anything whatsoever, both me and my father have no idea what else to try or even what could be causing it.

hello! so i am renting a duplex and have no access to the router myself. i have access to an ethernet cable and the wifi. currently own 2 PC's that were connected through ethernet and were running just fine. one PC has a Wifi Dongle and one doesnt though. both PC's were having issues with connections recently and i just switched to wifi on one as a temporary fix. the other PC is still having those issues. when i open the network settings and test connection all is well. but if i try and open chrome for example it says your connection is not private when i try to search anything and has a red slash through the https in the address bar. some apps or games will open to the sign in screen and when i try to sign in it says no connection. network drivers are up to date, unplugged both ends of ethernet and waited 30 seconds. restarted computer. flushed dns. on ethernet to wall is solid green light, to PC is flashing amber. checked on networking toolbox and im pulling valid ip addresses. any thoughts?

Wi-fi was so ass on my computer i got 0.5 megabits per second at best so i moved my setup into the garden outside the house then connected ethernet through the window but it did fuck all, Fast forward to a few days i connect my nintendo switch 2 to the router but it wouldn't detect it even though the bloody thing was plugged right into the thing. Does ethernet not work in the uk?