Wired ethernet speed slow

[WRSORBI]

I am having the same problem. It seems to have begun 2 weeks ago in my case when Windows11upgraded to 22H2.  It is only affected wired ports. WiFi unaffected. It is affecting every PC upgraded to 22H2 irrespective of NIC vendor; Intel, Realtek, etc nor brand of PC/laptop. My RBK852 is still under warranty and Netgear replaced it but the problem continues.  Wiring (with replaced Cat6 cables to be sure) directly to Netgear CM2000 modem yields consistent 1Gbs download yet wired to RBK852 and running Ookla’s SpeedTest shows wired speeds being gradually throttled from 789Mbps to ~230Mbp each time no matter what LAN port on router is used. Ookla SpeedTest on router consistently runs at ~1.4Gbps download/41Mbps up. ISP is Xfinity. Netgear tried changing MTU from default 1500 to 1492 but this made no difference.

[WRSORBI · Accepted solution]

Had a network tech friend bring his Asus GT AX-11000 to test in my home and we experienced the ethernet throttling the same even with the Asus.  He then turned off IPV6 on my NICs properties, rebooted, retested and problem is resolved.  I now have full ~920Mbps download on a 1GbE NIC as expected from using either the Asus or the RBK852 simply using IPV4. Circumvention is to turn of IPV6 in NIC properties.    

[WRSORBI]

Reposting to correct thread. I am having the same problem. It seems to have begun 2 weeks ago in my case when Windows11upgraded to 22H2.  It is only affected wired ports. WiFi unaffected. It is affecting every PC upgraded to 22H2 irrespective of NIC vendor; Intel, Realtek, etc nor brand of PC/laptop. My RBK852 is still under warranty and Netgear replaced it but the problem continues.  Wiring (with replaced Cat6 cables to be sure) directly to Netgear CM2000 modem yields consistent 1Gbs download yet wired to RBK852 and running Ookla’s SpeedTest shows wired speeds being gradually throttled from 789Mbps to ~230Mbp each time no matter what LAN port on router is used. Ookla SpeedTest on router consistently runs at ~1.4Gbps download/41Mbps up. ISP is Xfinity. Netgear tried changing MTU from default 1500 to 1492 but this made no difference. Of course, multiple factory reset and NIC driver u[dates performed to no avail.

[FURRYe38]

CAT6 A STP is recommended between the RBR and CM modem.

Is this the only device that your seeing this with? Does this happen on other PCs or different windows versions?

What is the brand and model of the ethernet adapter with in the PC? 

Ensure the ethernet adapter drivers are up to date.

Disable any ethernet adapter built in QoS features if it supports it.

Swap ethernet adapters to compare results

What is the size of your home? Sq Ft?
What is the distance between the router and 📡 satellite(s)? 30 feet or more is recommended in between RBR and RBS📡 to begin with depending upon building materials when wirelessly connected.
https://kb.netgear.com/31029/Where-should-I-place-my-Orbi-satellite 📡

Any of the following enabled?:
Armor, Circle, Traffic Meter

Has a power off for 1 minute then back ON with the ISP modem and router been performed since last update?
Be sure to restart your network in this sequence:
Turn off and unplug modem.
Turn off router and computers.
Plug in and turn on modem. Wait 2 minutes for it to connect.
Turn on the router and wait 2 minutes for it to connect.
Turn on computers and rest of network.

Has a factory reset and setup from scratch been performed since last FW update?

[WRSORBI]

My previous post did not make it for some reason.  All of what you mention has been verified and done ad nauseum.  Tests with Netgear support were extensive.  NICS are Intel, Killer and Realtek.  Results on each NIC the same when connected to RBR.  Satellite not part of problem.  Wifi speeds unaffected  Problem is only with the (4) 1GbE LAN ports on RBR850.  All NICS test full link speed when directly connected to Netgear CM2000 modem port. All cables confirmed in spec and are recent. No parental controls and Armor was tested with and without and made no difference,  RBR Speedtest below and video showing NIC throttling with Speedtest is at https://www.youtube.com/shorts/5_82G_0I3jQ

[FURRYe38]

So after the reset and setup from scratch the speed is good for a while then drops to a lower result? 

Is the CAT6 cable between the Modem and RBR a CAT6A STP? 

Are you testing different speed test servers on Ooklas speed test app to compare?

How many devices are connected entirely to the RBR? 

Are you speed testing while other devices are online or just a wired PC? 

FYI, Killer nics have there own QOS that can cause problems though if you tested with other nics, kinda doubt a nic problem. You should be seeing near 900Mpbs or just over all the time on the LAN ports. 

What Firmware version is currently loaded?

[WRSORBI]

These cables have all been verified with Netgear support.  Netgear CM2000 modem ships with 10GbE CAT6A STP yellow cable. Testing is done ONLY with NIC attached.  No other devices active.  Very aware of Killer Performance Suite and this is deinstalled on all PC's with Killer NIC's.  Have tried different server providers through Ookla, Fast,com, M-lab, Xfinity speed tests.  All same results.

After reset, after new modem, results are the same.  NIC ports are throttled.

[FURRYe38]

What Firmware version is currently loaded?

[WRSORBI]

meant after new router and satellite....not modem

[WRSORBI]

firmware is latest Firmware Version
V4.6.9.11_2.3.5

[FURRYe38]

Sounds like possible the RBR maybe faulty. 

[WRSORBI]

new router and satellite replaced by Netgear this past Friday.  So this is RBK852 number 2 under warranty

[FURRYe38]

Ok. Dang. 

[CrimpOn]

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@WRSORBI wrote:

when Windows11upgraded to 22H2.

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Just a random question:  Have you tried rolling back one of the Windows systems to before the 22H2 upgrade?

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@WRSORBI wrote:

wired to RBK852 and running Ookla’s SpeedTest shows wired speeds being gradually throttled from 789Mbps to ~230Mbp

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The way I read this, when Ookla Speed Test is run repeatedly on one PC, the reported results fall from something close to 800MB/s, with each result being less than the previous result, until finally reaching just over 200MB/s, where it remains?  i.e. a constant progression?

After one PC has gone through this, what happens when another PC does the same thing?  Does it begin high and gradually decrease?

[WRSORBI]

Windows reimage was done but it immediately upgraded to 22H2.  Problem occurs on all PC's/laptops.  4 different ones have been tried. The speedtests downloads all initiate at ~800Mbps and during the speedtest throttle down to ~300Mbps or less.  See previously provided youtube

[FURRYe38]

And all PCs have this same version of Windows? 

[WRSORBI]

yes.  The latest Windows 11 22H2 build 22621.675

[FURRYe38]

Any chance you have a Windows 10 PC?

Any chance of you testing Windows 11 out with out it updating to the resent service release just to see if it still happens? 

[WRSORBI]

I'll try to borrow a Windows PC that has not upgraded.  May take a couple of days.

[FURRYe38]

👍

[CrimpOn]

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@WRSORBI wrote:

Windows reimage was done but it immediately upgraded to 22H2.  Problem occurs on all PC's/laptops.  4 different ones have been tried. The speedtests downloads all initiate at ~800Mbps and during the speedtest throttle down to ~300Mbps or less.  See previously provided youtube

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Thanks. My Bad for not watching the video.  I see the tests beginning at one speed, then very quickly dropping into the 300's and "bouncing around" for the remainder of the test.  Not a typical Speed Test pattern at all.

My Windows 10 offers an option to "Pause" updates:

Does Windows 11 not offer that option?  One tactic might be to disconnect from the internet, do the Restore, Set the option to postpone updates, then reconnect to the internet.

It would be a fine "Howdy Do" if the Windows software upgrade causes this phenomenon.  Netgear makes all of the Ethernet chipsets in this configuration:

• The 2.5G Ethernet port in the CM2000
• The 2.5G Ethernet port in the RBR850
• The (4) port Gigabit LAN module in the RBR850

[WRSORBI]

I'm going to try to borrow another PC this week that is not at this 22h2 level and try it out.  I'll report back then.

[CrimpOn]

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@WRSORBI wrote:

I'm going to try to borrow another PC this week that is not at this 22h2 level and try it out.  I'll report back then.

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That will probably introduce another variable, unless that PC has one of the same Ethernet ports as the current PCs.

By the way, Wireshark capture shows Speed Test packets consist of a payload of 1,460 bytes plus Ethernet overhead which totals 1,514 bytes "on the wire", which is less than the maximum length of 1,526 bytes.  That is probably the reason that changing the MTU value from 1,500 to 1,492 made no difference.

As long as you are having fun, it might be entertaining to do an iperf3 test between two computers attached to the router.  On my aging RBR50, with two 7 year old PCs, I consistently get about 980MB/s.  I would think that an iperf3 test will bypass the router CPU entirely and remain entirely within the LAN Ethernet module.

[FURRYe38]

OK heres my RBR850 with a 2.5Gb connection to a CAX80 in modem mode:

ISP doesn't have anything higher than 1Gb on the WAN currently. 

ASRock Windows 10x64 21H2 PC:

HP x640 Windows 11x64 21H2 PC:

Ran these test 3 times on each PC to be sure. 

RBR Connection rates:

[WRSORBI]

Thanks Furry.  Is it 21H2?  This is a previous Win 11 previous build.  Current is 22H2.

[CrimpOn]

I believe there are both 21H2 and 22H2 builds available for both Windows 10 and Windows 11.  (My Windows 10 is on 22H2)

This is fascinating as @FURRYe38 is getting full speed from the 850 from both Windows 10 and Windows 11 on release 21H2.

The significant difference appears to be release 22H2. (which was the original observation)

(Also, it staggers the mind that Microsoft could have done anything that would mess with something so fundamental as Ethernet and only affect the Orbi Ethernet LAN.  How would a person even look for something like that ?  Maybe the Ethernet adapter Advanced Properties?)