Question Ethernet keeps changing from 1Gbps to 100Mbps

[liam.walby14]

As the title says, My ethernet link speed keeps changing to 100Mbps.

PC Specs:
Ryzen 7700x
Asus ROG STRIX B650-A GAMING WIFI
32Gb DDR5 Corsair Vengeance
RTX 2080

Network:
Virgin Media Hub 5
Netgear GS308

My network is as follows:
Router (1Gbps download) > around a 15 meter Cat6e Externally rated Ethernet > 8 Port Netgear GS308 Network switch > Cat 6e ethernet to main PC and work laptop (Plus other devices).

My PC motherboard has 10Gbps ethernet.

My work laptop which is tied into the same network switch with the exact same ethernet cable gets the full 1Gbps speed and doesn't keep changing , My PC only gets 100Mbps, well it caps itself at this speed. If I constantly keeping changing the port the ethernet is plugged into on the switch it get the full 1Gbps speed, If I then turn my PC off and back on it will cap at 100Mbps. I have changed the Speed&Duplex setting to 1Gbps, 2.5Gbps, Auto negotiate etc and no matter what it just keeps reverting back to 100Mbps. I have edited power plans and all the other settings but it goes back to 100Mbps.

No matter what I do it keeps reverting back so any help would be greatly appreciated.

 

[Ralston18]

Update your post to include full system hardware specs and OS information for your PC.

Make and model information for modem, router, or modem/router (if combined)?

Any wireless devices?

On your PC (wired) verify that only the Ethernet adapter is enabled. Wireless and other ethernet adapters should be disabled.

On your PC also run "ipconfig /all" (without quotes) via the Command Prompt.

Copy the full results and post accordingly.

 

[liam.walby14]

Update your post to include full system hardware specs and OS information for your PC.

Make and model information for modem, router, or modem/router (if combined)?

Any wireless devices?

On your PC (wired) verify that only the Ethernet adapter is enabled. Wireless and other ethernet adapters should be disabled.

On your PC also run "ipconfig /all" (without quotes) via the Command Prompt.

Copy the full results and post accordingly.

Post updated accordingly

All other network adapter are disabled/ Not connected

Results from IPConfig /all:
C:\Windows\System32>ipconfig /all

Windows IP Configuration

Host Name . . . . . . . . . . . . : DESKTOP-A5CLOKO
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : cable.virginm.net

Ethernet adapter vEthernet (Default Switch (WiFi 2)):

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Hyper-V Virtual Ethernet Adapter #3
Physical Address. . . . . . . . . : 00-15-5D-67-73-25
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

Wireless LAN adapter WiFi 2:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . : cable.virginm.net
Description . . . . . . . . . . . : MediaTek Wi-Fi 6E MT7922 (RZ616) 160MHz Wireless LAN Card
Physical Address. . . . . . . . . : D8-80-83-82-46-21
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes

Wireless LAN adapter Local Area Connection* 11:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft Wi-Fi Direct Virtual Adapter #3
Physical Address. . . . . . . . . : DA-80-83-82-66-01
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes

Wireless LAN adapter Local Area Connection* 12:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Microsoft Wi-Fi Direct Virtual Adapter #4
Physical Address. . . . . . . . . : DA-80-83-82-76-11
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes

Ethernet adapter Ethernet:

Connection-specific DNS Suffix . : cable.virginm.net
Description . . . . . . . . . . . : Intel(R) Ethernet Controller (3) I225-V
Physical Address. . . . . . . . . : C8-7F-54-67-77-58
DHCP Enabled. . . . . . . . . . . : Yes
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::4c39:1a3e:a8e5:751%2(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.0.249(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.255.0
Lease Obtained. . . . . . . . . . : 16 May 2024 12:42:15
Lease Expires . . . . . . . . . . : 17 May 2024 12:42:16
Default Gateway . . . . . . . . . : 192.168.0.1
DHCP Server . . . . . . . . . . . : 192.168.0.1
DHCPv6 IAID . . . . . . . . . . . : 80248660
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-2C-B2-86-71-C8-7F-54-67-77-58
DNS Servers . . . . . . . . . . . : 194.168.4.100
194.168.8.100
NetBIOS over Tcpip. . . . . . . . : Enabled

Ethernet adapter vEthernet (Default Switch):

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Hyper-V Virtual Ethernet Adapter
Physical Address. . . . . . . . . : 00-15-5D-C9-47-CF
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::7cb9:896f:7366:c510%27(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.224.1(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.240.0
Default Gateway . . . . . . . . . :
DHCPv6 IAID . . . . . . . . . . . : 452990301
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-2C-B2-86-71-C8-7F-54-67-77-58
NetBIOS over Tcpip. . . . . . . . : Enabled

 

[kanewolf]

As the title says, My ethernet link speed keeps changing to 100Mbps.

PC Specs:
Ryzen 7700x
Asus ROG STRIX B650-A GAMING WIFI
32Gb DDR5 Corsair Vengeance
RTX 2080

Network:
Virgin Media Hub 5
Netgear GS308

My network is as follows:
Router (1Gbps download) > around a 15 meter Cat6e Externally rated Ethernet > 8 Port Netgear GS308 Network switch > Cat 6e ethernet to main PC and work laptop (Plus other devices).

My PC motherboard has 10Gbps ethernet.

My work laptop which is tied into the same network switch with the exact same ethernet cable gets the full 1Gbps speed and doesn't keep changing , My PC only gets 100Mbps, well it caps itself at this speed. If I constantly keeping changing the port the ethernet is plugged into on the switch it get the full 1Gbps speed, If I then turn my PC off and back on it will cap at 100Mbps. I have changed the Speed&Duplex setting to 1Gbps, 2.5Gbps, Auto negotiate etc and no matter what it just keeps reverting back to 100Mbps. I have edited power plans and all the other settings but it goes back to 100Mbps.

No matter what I do it keeps reverting back so any help would be greatly appreciated.

99/100 times this is a cable problem. There are many fake cables sold. Since cat5e cables are fine, get a new, round, 100% copper cat 5e or 6a cable.

 

[liam.walby14]

99/100 times this is a cable problem. There are many fake cables sold. Since cat5e cables are fine, get a new, round, 100% copper cat 5e or 6a cable.

The Cable isn't a pre-made cable.

I made the cable myself using Cat6e round 100% copper cable. I also use the same type of cable and have used the exact cable from my PC on my work laptop and that has no issues, so that is not a valid opinion.

 

[Ralston18]

On your PC did you create that virtual switch?

= = = =

As for the Intel(R) Ethernet Controller (3) I225-V:

At the time of ipconfig your PC was requesting a DHCP IP address from a router (Default Gateway) at 192.168.0.1 (subnet 255.255.255.0) and being assigned the DHCP IP address of 192.168.0.249.

Assigned DHCP IP addresses can and do change.

IP address lease time is only 24 hours. Should not make a difference per se but I would use the max time allowed by the router. Barring specific reasons for not doing so. The router's admin person will need to make that change.

Change the DNS servers to Google at 8.8.8.8 and 8.8.4.4

Also: disabling IPv6 has proven helpful for many users.

 

[liam.walby14]

On your PC did you create that virtual switch?

= = = =

As for the Intel(R) Ethernet Controller (3) I225-V:

At the time of ipconfig your PC was requesting a DHCP IP address from a router (Default Gateway) at 192.168.0.1 (subnet 255.255.255.0) and being assigned the DHCP IP address of 192.168.0.249.

Assigned DHCP IP addresses can and do change.

IP address lease time is only 24 hours. Should not make a difference per se but I would use the max time allowed by the router. Barring specific reasons for not doing so. The router's admin person will need to make that change.

Change the DNS servers to Google at 8.8.8.8 and 8.8.4.4

Also: disabling IPv6 has proven helpful for many users.

No, I haven't created any Virtual switches. Only switch I have is the 8 port network switch

"IP address lease time is only 24 hours. Should not make a difference per se but I would use the max time allowed by the router. Barring specific reasons for not doing so. The router's admin person will need to make that change." - When you say make that change? what change are you talking about? I can access the admin portal for my router.

I have disabled IPv6 and it proved ineffective.

 

[kanewolf]

The Cable isn't a pre-made cable.

I made the cable myself using Cat6e round 100% copper cable. I also use the same type of cable and have used the exact cable from my PC on my work laptop and that has no issues, so that is not a valid opinion.

Then you should get factory made cables. It takes practice to be good at terminating ethernet.
It is a valid observation. Ethernet ports, have different tolerance for out-of-spec cables. Working on your laptop is NOT a guarantee that it will work for your 2.5GE port on your desktop.

 

[liam.walby14]

Then you should get factory made cables. It takes practice to be good at terminating ethernet.
It is a valid observation. Ethernet ports, have different tolerance for out-of-spec cables. Working on your laptop is NOT a guarantee that it will work for your 2.5GE port on your desktop.

I am an IT System admin and Sever administrator. I have seen my fair share of cables and terminated a fair share of cables so I think I know what to do when it comes to making an ethernet cable.

"Ethernet ports, have different tolerance for out-of-spec cables. Working on your laptop is NOT a guarantee that it will work for your 2.5GE port on your desktop." That's valid yes - However, as I stated I have tried my PC cable and other cables in the work laptop and it gets full speed, I tried my laptop cable in my PC and it was still capped. The cable is not the problem as if it was, the problem would have been sorted when trying another cable.

 

[bill001g]

If your positive it is not the cable you made then buy a new motherboard.
The speed negotiation is a hardware function done by the chips measuring things like voltages and resistances it is not software that can be loaded or patched.

You can also buy a PCIE based add in card or a USB card but it needs to run on a USB3 port.

It is very very rare for it to be a port problem.

 

[liam.walby14]

If your positive it is not the cable you made then buy a new motherboard.
The speed negotiation is a hardware function done by the chips measuring things like voltages and resistances it is not software that can be loaded or patched.

You can also buy a PCIE based add in card or a USB card but it needs to run on a USB3 port.

It is very very rare for it to be a port problem.

I might try an add in card, Can you recommend one?

Worst thing that can happen is it doesn't fix it and I can return it.

 

[kanewolf]

I am an IT System admin and Sever administrator. I have seen my fair share of cables and terminated a fair share of cables so I think I know what to do when it comes to making an ethernet cable.

No mater how many cables you have terminated, you are never as good as factory made cables from a quality supplier.

 

[Ralston18]

No, I haven't created any Virtual switches. Only switch I have is the 8 port network switch

"IP address lease time is only 24 hours. Should not make a difference per se but I would use the max time allowed by the router. Barring specific reasons for not doing so. The router's admin person will need to make that change." - When you say make that change? what change are you talking about? I can access the admin portal for my router.

I have disabled IPv6 and it proved ineffective.

Lease time.

 

[Ralston18]

Also:

1) I am also wondering about the cable(s). One way or another you should swap in a known working (at required speed) factory made cable.

2) Not in my comfort zone (full disclosure) but if "ipconfig" is showing a virtual switch that you did not create then something seems amiss. What is the VM environment? I will defer to those with applicable knowledge and experience regarding the presence of the virtual switch.

3) What about Google/DNS servers - did that make any difference?

 

[liam.walby14]

Also:

1) I am also wondering about the cable(s). One way or another you should swap in a known working (at required speed) factory made cable.

2) Not in my comfort zone (full disclosure) but if "ipconfig" is showing a virtual switch that you did not create then something seems amiss. What is the VM environment? I will defer to those with applicable knowledge and experience regarding the presence of the virtual switch.

3) What about Google/DNS servers - did that make any difference?

Would the switch be showing within there for my 8 port switch? would that potentially be what that is as I cannot see any other network adapters or switches other than my Ethernet and WIFI?

DNS servers made no difference unfortunately.

 

[Ralston18]

Switch being (from "ipconfig /all" via Post #3 ):

"Ethernet adapter vEthernet (Default Switch):

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Hyper-V Virtual Ethernet Adapter
Physical Address. . . . . . . . . : 00-15-5D-C9-47-CF
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::7cb9:896f:7366:c510%27(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.224.1(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.240.0
Default Gateway . . . . . . . . . :
DHCPv6 IAID . . . . . . . . . . . : 452990301
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-2C-B2-86-71-C8-7F-54-67-77-58
NetBIOS over Tcpip. . . . . . . . : Enabled"

If there is no apparent reason for that "Default switch" then that is a possible reason or clue regarding what is happening.

There should be only one network adapter enabled on the PC in question barring specific reasons for using multiple adapters. And you would be aware of that and the reasons for doing so.

One immediate option would be to disable the "Default switch"/"Virtual Ethernet Adapter" from the PC.

However, without more information or knowledge on my part, my recommendation is to simply hold on the matter for the time being.

There may be other ideas and suggestions.

 

[liam.walby14]

Switch being (from "ipconfig /all" via Post #3 ):

"Ethernet adapter vEthernet (Default Switch):

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Hyper-V Virtual Ethernet Adapter
Physical Address. . . . . . . . . : 00-15-5D-C9-47-CF
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes
Link-local IPv6 Address . . . . . : fe80::7cb9:896f:7366:c510%27(Preferred)
IPv4 Address. . . . . . . . . . . : 192.168.224.1(Preferred)
Subnet Mask . . . . . . . . . . . : 255.255.240.0
Default Gateway . . . . . . . . . :
DHCPv6 IAID . . . . . . . . . . . : 452990301
DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-2C-B2-86-71-C8-7F-54-67-77-58
NetBIOS over Tcpip. . . . . . . . : Enabled"

If there is no apparent reason for that "Default switch" then that is a possible reason or clue regarding what is happening.

There should be only one network adapter enabled on the PC in question barring specific reasons for using multiple adapters. And you would be aware of that and the reasons for doing so.

One immediate option would be to disable the "Default switch"/"Virtual Ethernet Adapter" from the PC.

However, without more information or knowledge on my part, my recommendation is to simply hold on the matter for the time being.

There may be other ideas and suggestions.

Thanks for that reply.

That switch appears no where on my machine other than on ipconfig /all, I have checked device manager, Control panel but for the life of me cannot see anything that points to it

 

[JeffreyP55]

The Cable isn't a pre-made cable.

I made the cable myself using Cat6e round 100% copper cable. I also use the same type of cable and have used the exact cable from my PC on my work laptop and that has no issues, so that is not a valid opinion.

Did you double check the pin out when terminating the twisted pair then ring it out? I make mine also. It doesn't take much to be miswired,
https://www.cableorganizer.com/learning-center/how-to/how-to-terminate-RJ45.htm

 

[liam.walby14]

Did you double check the pin out when terminating the twisted pair then ring it out? I make mine also. It doesn't take much to be miswired,
https://www.cableorganizer.com/learning-center/how-to/how-to-terminate-RJ45.htm

Yep double checked, triple checked. All passed fine through a tester also

 

[Ralston18]

@liam.walby14

Reference: Hyper-V Virtual Ethernet Adapter

FYI

https://learn.microsoft.com/en-us/w...hyper-v-virtual-machines?tabs=hyper-v-manager

https://www.dell.com/support/manual...b4ffe0-6247-4a75-8b66-222bfd2cc50a&lang=en-us

Referencing the second link: use Control Panel to determine if Hyper V is turned on or off.

And, if on, is that expected or required?

 

[liam.walby14]

So, Just to give an update in regard to this thread.

Firstly thank you for the replies, Gained some useful knowledge.

I have managed to fix the issue with a 2.5Gb Ethernet add-in card, Further proving that the issue was in fact hardware related rather than internet/ cable related. I have used this card now for around a week and the Link speed has not dropped from 1000/1000 Mbps (touch wood).