Solved Could W11 Workstation 6 plus cores cause fault with NIC but not WiFi?

NOTICE: This is a "double post". Matter of fact, it is a triple post. I have given this a lot of time on two other boards relative to the issue and not received an answer, so i will now post here where i probably should have started. Besides the site stated a few lines herebelow, the nearly identical post appears at Could W11 Workstation 6 plus cores cause fault with NIC but not WiFi?

In that upper level Dell support has quit responding, i wish to be as definitive in my next moves as possible. As much as i sympathize with their frustration with me for twice i thought the issue resolved only for it to surface again, they either have stopped responding because they consider me a harassing lunatic (unintentionally), or that they are aware of a fault in their product and do not want to pay to make me (or anyone else so affected) whole; i can't see any alternative.

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Thank you VERY much for your consideration; i definitely need help of those smarter than i-

As i am not making any progress at https://answers.microsoft.com/en-us...-support/31a62525-096e-4cc1-91f0-8082ef183dda i wish to post almost the same question here for your consideration, but instead of "How do i contact upper level MS support", i would like to provide the following information and ask if it is more probable that the issue is with the OS (Windows 11 Workstation), as in the first of the five proposed options for fault i offer near the end of the following, if it would be with one of the last four of the five options, or if there are any additional options i have not considered-

System info is at the end-

---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
ISSUE:

1. With a wired internet connection Outlook will fail to send emails almost always from a Microsoft Exchange Account if the email has attachments. I use three email accounts - two are through Exchange servers and one is with Apple iCloud. The fault occurs with either (both) MS Exchange account(s).
2. The same email will send without issue from either:
   1. Using a WiFi connection on either MS Exchange Account, or
   2. From the wired connection if i switch the sending Outlook Account to my Apple iCloud account.

ATTEMPTED RESOLUTION:

Since this problem started in early December, 2022, at the time that i installed this new Dell Precision 3650 Tower i have:

1. Reinstalled Outlook (numerous times)
2. Consulted GoDaddy tech support
3. Consulted Verizon tech support
4. Consulted Microsoft 365 tech support
5. Consulted Dell tech support
6. Ran emails from the Outlook web interface without issue
7. Connected an old laptop (it had to run about three years' worth of updates) and that ran and sent emails with large attachments from Outlook through both MS Exchange accounts without issue (running Windows 10 Pro).
8. Ran Outlook in Safe mode
9. Deleted as many directories i could find (normal and "hidden"), and deleted about every registry value that had the word "Outlook" in it.
10. Made numerous adjustments to my ip address, gateway address and DNS servers so the wired was identical to the WiFi, under the extensive supervision of upper level Dell tech support Brian T. Rich Manager 2, Technical Support.
11. Have had MS365 support remote into my computer numerous times and attempt to find root cause.
12. Run SFC (several times on various occasions).
13. Ran a Repair for W11
14. Reinstalled Windows 11 Workstation for 6 Cores + (a couple of times)
15. Created more Outlook Profiles than i care to count (multitude of times at different occasions)
16. Run Outlook with both Defender and Malwarebytes (my only firewall/malware programs previous to installing Glasswire) turned completely off (with and without reboots).
17. Wiped out and replaced the prior Outlook accounts (that appear to be stored on the servers)
18. Wiped the OS disk entirely clean (re-partitioned and reformatted it), then re-installed Windows 11 and MS365.
19. Dell replaced the motherboard (i am using the on-board NIC). Used the same model of motherboard, refusing to install an upgraded model motherboard as i requested which i wanted to eliminate the possibility of an inherent motherboard defect, which they dismissed as improbable.
20. Tried three different cables from the router to the computer
    1. Prior Cat 6 that was working perfectly with the prior computer
    2. New Cat 6
    3. New Cat 8
21. Have had Verizon FIOS run multiple tests and updates
22. Replaced the Verizon FIOS router with a new one
23. Replaced the cable from the wall to the router with a new one.

I have spent days with Microsoft 365 tech support, along with GoDaddy, Verizon and Dell tech support, and probably too many other items that escape enumeration at this time.

PROPOSED CONSIDERATIONS AT THIS TIME:

I can only think of five items left that might be the issue (other than govt or extraterrestrial intervention, which we will table for the time being):

1. Windows 11 for Workstations with 6 or more cores defect (I have only used Windows Pro prior, last was W10 Pro up to the point of swapping in the new computer).
2. Xeon CPU on the Dell Precision 3650 (Never had a Xeon CPU before. Same CPU was swapped to the new motherboard)
3. BIOS flaw for the BIOS distributed and updated with the motherboards as built into the Dell Precision 3650
4. Chipset issues on the Dell Precision 3650
5. Inherent flaw in the motherboard manufacture of the Dell Precision 3650 (please remember that Dell did swap in a new motherboard)

Unfortunately, to swap the old computer back in is not an option (from which i NEVER had issues sending emails, same connection), but given Outlook performed fine on the old laptop that i tried (as cited hereabove), i doubt the old computer would yield any new information.

My focus on these five items above is because the prior computer i was running under Windows 10 Pro which did not have a Xeon processor had no issues; i only replaced it because it was something around 13 to 15 years old so it was relatively slow.

I did ask Dell (Mr. Rich) for contact information for the motherboard manufacturer twice. Neither time has he responded.

Since it appears that ALL tech support resources with each of the four companies above named have abandoned all further support to me on this issue, i wish to now define the most likely culprit and with focus demand a higher level of assistance, publically if need be. It seems reasonable that i can strike Verizon and GoDaddy at this point, so the weight falls upon Microsoft or Dell.

With Microsoft, the issue, as far as i can only tell, could only fall as an incompatibility between the OS or Outlook and the hardware/firmware as provided by Dell. I have to parenthetically mention that since Dell did supply the product in it's entirety, i would think somehow that they should provide support until the issue is resolved. Apparently they do not think so. Any lawyers out there want to weigh in?

With Dell, we have the potential that the hardware they supplied is not compatible with an installation of W11 Workstation 6+ cores and/or Outlook on a wired connection or by the means of items 2 through 5, or, perhaps, something i have not considered.

Could someone who really knows what they are doing provide me with some guidance here please? Someone's tech support is improperly hanging me out to dry, not taking any responsibility for the fault, which i find very offensive and an act against anyone and everyone who would buy their product.

I certainly can continue working via WiFi, but i'd rather be wired after spending the money to be able to do so!

Device name Rafiki
Processor Intel(R) Xeon(R) W-1370P @ 3.60GHz 3.60 GHz
Installed RAM16.0 GB (15.7 GB usable)
Device ID3B3F6463-0503-4BE7-98A5-45740BA2A2F5
Product ID00391-50000-00000-AAOEM
System type 64-bit operating system, x64-based processor
Pen and touch No pen or touch input is available for this display
Edition Windows 11 Pro for Workstations
Version22H2
Installed on‎12/‎28/‎2022
OS build22621.1105
Experience Windows Feature Experience Pack 1000.22638.1000.0

Dont use either system,,
but my first thought would be is the Ethernet connection via a Domain link with a attachment block rule in Outlook,wheras Wifi is a connection to your ISP

OK torchwood, you just flew right over my head (but THANKS for an answer!!!)!

What is meant by "Ethernet connection via a Domain link with a attachment block rule in Outlook"?

My confusion is as this is the exact same Ethernet connection that was working flawlessly with the computer that was there 10 to 15 minutes prior to swapping this one in back in early December, and i have deleted and reinstalled Outlook many times with many profiles in both normal and safe modes, so i don't understand exactly where i should be looking for the bug-

Stupid question, do you have Verizon FIOS? Just a hunch. Dell Precision 3650 has an I219-LM NIC (networking chip).

Blame Verizon, their ONT (FIOS router) has a known firmware issue which breaks high-bandwidth network traffic with specific Intel chipsets, namely I219-based NIC's. I've only heard of this story from ASUS owners, but Dell wouldn't be immune to this fault.

The normal signs:
- Any network tasks that involve a high data transfer fail (Outlook attachments, video streaming)
- WiFi on the same FIOS box works normally
- Disabling IPv6 on your Ethernet interface, and using IPv4-only fixes the problem

Your old laptop probably has a different NIC chipset.

Download Intel's fix script:
Disabling TCP-IPv6 Checksum Offload Capability with Intel® 1/10 GbE Controllers

I'm honestly surprised Verizon level 2 support has no clue. Don't blame MS or Dell, since only Verizon is responsible for the vendor who manufactures their network gear.
Ethernet not working, WiFi works

Thank you!

DEFINITELY Verizon FIOS.

Will give a try to fix, will report!


Edit: I ain't gonna light the cigar quite yet as i have had false positives before as mentioned, but concurrent with initial tests i hear the fat lady warming up to sing!!!

I'm going to continue sampling into tomorrow morning when i think i can finally declare it done with. In the meantime, i do have a question for you that i ask without prejudice nor preference - What exactly makes this a Verizon equipment issue instead of an intel chip issue? Is it that the chips were produced before the ONT? I am confused as it would seem to me that the ONT was working fine with the other chips out there. Did the company that manufactures the ONT do something that violates the protocol rules? Strictly out of curiosity, but presently amazed at how quickly you solved (i really hope) what everyone else could not!!!

Supposedly, the technical answer is Verizon's ONT re-packs IPv6 traffic with "extra" non-data bytes. Intel's TCP offloading will compare the checksum inside the packet frame for consistency. The extra bytes throw off the checksum, so the driver discards it as "corrupted".

Basically, Intel says nope and Windows never sees the missing traffic.

Why do I say it's Verizon's fault? Intel I219 is a very popular chipset on modern PC's, and if this problem was widespread -- everyone would know. And IPv4 and WiFi sessions work perfectly fine on the same ONT. Draw your own conclusions.

PS -- I'm not a Verizon client, but an acquaintance shared his sad tale about choppy YouTube streaming, and broken e-mail syncing. He and his friend (both Verizon) had the exact same problems. After he lucked into disabling IPv6, I was confused why that made any difference.

Using my Google "skills", tracked down the Verizon community postings where other folks confirmed it.

I hope you find the time to thank Dell and MS support, for trying.

Thank you.

Given this background, i too find it strange that the higher level Verizon tech support did not identify the issue, but i do believe he was trying in good faith.

The issue seems to be with that which they call their 5th Generation routers. Now, the interesting part - though one can get a 6th generation router, you have to accept a new agreement and pay an extra $20/month and get a $200 gift card, or pay a figure in the low $400's for one. If you are requesting because of the fault, i'm sorry but none are available for rent. For marketing, yes; for failure, no. Kind of convoluted i think-

I don't have your hardware but I'm 100% sure the problem lies with the providers rather than with the computer's BIOS etc especially if the firmware is up to date.

I have zero problems with 3 Icelandic email accounts (own domains) whether I'm using Wifi or LAN (cabled connection) or whether I'm in Iceland or working (generally in the EU - Usually Belguim, France, Hollland or Germany).

It's possible some very high speed fibre broadband exceeds the capacity of some servers to handle it -- we are getting 1 Tbps being rolled out soon which should be interesting. 1 - 10 Gbps currently. Note also some wifi cards and protocols have the theoretical possibility of around 1 Gbps but with half duplex etc traffic is slower. and so might pass any problems ISP has with email etc.

Cheers
jimbo

After what i consider enough testing (i really, really, hope) i am lighting a cigar, throwing a party, thanking God for you (really!), and closing this!!!

Many thanks garlin, so much appreciated and humbled.

Going to let the folks that tried know the solution to help them and other people who come to them in the future now-

@garlin - if i could draw upon your knowledge one more time - Why would the emails send when i used my Apple iCloud account to send them? At this point the issue appears resolved in that after some 5 to 10 tests over the last day all MS Exchange email sends with large attachments have gone without fault, but should not the same error have compromised the Apple account from the same email client (Outlook)?

Don't know why iCloud would be different, unless Apple servers tends to limit transfer rates.