[BUG] Network regression on Linux 6.16.1 -> 6.16.2 (persists in 6.16.3): intermittent IPv4 traffic on Wi-Fi and Ethernet

[BUG] Network regression on Linux 6.16.1 -> 6.16.2 (persists in 6.16.3): intermittent IPv4 traffic on Wi-Fi and Ethernet

[Luis Alberto]

Hi everyone, I’m new to this mailing list.

I am reporting a network regression observed on my system when
upgrading from Linux kernel 6.16.1 to 6.16.2 (and persisting in
6.16.3). The issue affects both Wi-Fi and Ethernet interfaces and
seems to originate in the kernel networking stack rather than any
specific driver.

For reference, I initially reported this issue on Bugzilla, ID 220484,
thinking it was exclusively a Wi-Fi problem.
Subsequent testing with a wired Ethernet connection confirmed that the
issue affects both interfaces.

System / hardware information:
- Motherboard: Asus TUF GAMING B460M-PLUS (WI-FI)
- CPU: Intel i5-10400
- 16GB RAM
- GPU: NVIDIA 4060 (proprietary open module drivers installed v580)
- Wi-Fi: Intel AX200, driver: iwlwifi + mac80211
- Ethernet: Intel I219-V, driver: e1000e
- Connections use IPv4

Kernel versions tested:
  6.15.7, 6.15.8 and 6.16.1 (works fine)
  6.16.2 and 6.16.3 (regression present)
  LTS 6.12.43 from Aug 20 (regression present)

Symptoms:
- Internet connectivity is intermittent: when opening multiple
websites simultaneously (e.g., 10 pages), roughly 1/4 fail to load.
- Failed pages either remain completely blank with a connection error
or load partially; both situations occur frequently.
- The issue also occurs occasionally with a single webpage, or when
downloading system updates, not limited to the browser.
- Occurs on both Wi-Fi and wired Ethernet.
- No connection drops; the interface remains "up".
- Tested in more than one distro: EndeavourOS and Nobara, vanilla installations.
- Ping comparison:
  6.16.2+: Running ping google.com while opening 10 webpages
successively results in >10% packet loss and several pages failing to
load.
  6.16.1: 0% packet loss and all pages load correctly on first
attempt, consistently.

Actions taken:
- Opened a Bugzilla report, ID 220484, including dmesg, journal, and
tcpdump logs.
- Tested with both Wi-Fi and Ethernet; issue persists on both.
- Verified IPv4 usage; IPv6 is link-local only.
- Tested repeatedly on kernel 6.16.1 and earlier: everything works perfectly.

Reproduction steps:
1. Boot kernel 6.16.2 or 6.16.3
2. Connect via Wi-Fi or Ethernet
3. Attempt to load multiple websites
4. Observe inconsistent traffic and intermittent failures

Any help is much appreciated.

Could anyone advise which commits between 6.16.1 and 6.16.2 might have
introduced this behavior, or suggest any testing and further steps?

Thank you very much.

Best regards,
Luis Alberto

Re: [BUG] Network regression on Linux 6.16.1 -> 6.16.2 (persists in 6.16.3): intermittent IPv4 traffic on Wi-Fi and Ethernet

[Eric Dumazet]

On 8/26/25 10:59 AM, Luis Alberto wrote:
> Hi everyone, I’m new to this mailing list.
>
> I am reporting a network regression observed on my system when
> upgrading from Linux kernel 6.16.1 to 6.16.2 (and persisting in
> 6.16.3). The issue affects both Wi-Fi and Ethernet interfaces and
> seems to originate in the kernel networking stack rather than any
> specific driver.
>
> For reference, I initially reported this issue on Bugzilla, ID 220484,
> thinking it was exclusively a Wi-Fi problem.
> Subsequent testing with a wired Ethernet connection confirmed that the
> issue affects both interfaces.
>
> System / hardware information:
> - Motherboard: Asus TUF GAMING B460M-PLUS (WI-FI)
> - CPU: Intel i5-10400
> - 16GB RAM
> - GPU: NVIDIA 4060 (proprietary open module drivers installed v580)
> - Wi-Fi: Intel AX200, driver: iwlwifi + mac80211
> - Ethernet: Intel I219-V, driver: e1000e
> - Connections use IPv4
>
> Kernel versions tested:
>    6.15.7, 6.15.8 and 6.16.1 (works fine)
>    6.16.2 and 6.16.3 (regression present)
>    LTS 6.12.43 from Aug 20 (regression present)
>
> Symptoms:
> - Internet connectivity is intermittent: when opening multiple
> websites simultaneously (e.g., 10 pages), roughly 1/4 fail to load.
> - Failed pages either remain completely blank with a connection error
> or load partially; both situations occur frequently.
> - The issue also occurs occasionally with a single webpage, or when
> downloading system updates, not limited to the browser.
> - Occurs on both Wi-Fi and wired Ethernet.
> - No connection drops; the interface remains "up".
> - Tested in more than one distro: EndeavourOS and Nobara, vanilla installations.
> - Ping comparison:
>    6.16.2+: Running ping google.com while opening 10 webpages
> successively results in >10% packet loss and several pages failing to
> load.
>    6.16.1: 0% packet loss and all pages load correctly on first
> attempt, consistently.
>
> Actions taken:
> - Opened a Bugzilla report, ID 220484, including dmesg, journal, and
> tcpdump logs.
> - Tested with both Wi-Fi and Ethernet; issue persists on both.
> - Verified IPv4 usage; IPv6 is link-local only.
> - Tested repeatedly on kernel 6.16.1 and earlier: everything works perfectly.
>
> Reproduction steps:
> 1. Boot kernel 6.16.2 or 6.16.3
> 2. Connect via Wi-Fi or Ethernet
> 3. Attempt to load multiple websites
> 4. Observe inconsistent traffic and intermittent failures
>
> Any help is much appreciated.
>
> Could anyone advise which commits between 6.16.1 and 6.16.2 might have
> introduced this behavior, or suggest any testing and further steps?
>
> Thank you very much.
>
> Best regards,
> Luis Alberto


Please try : 
https://lore.kernel.org/all/20250821105806.1453833-1-wangzijie1@honor.com 
<https://lore.kernel.org/all/20250821105806.1453833-1-wangzijie1@honor.com>


>

Re: [BUG] Network regression on Linux 6.16.1 -> 6.16.2 (persists in 6.16.3): intermittent IPv4 traffic on Wi-Fi and Ethernet

[Luis Alberto]

Hi,
Thanks for your reply and suggestions. The proposed fix didn’t solve my issue.

I’ve been running more tests and noticed something interesting:

Recent Kernels that work fine (issue solved, internet working perfectly):

6.16.3-201.nobara.fc42.x86_64
6.16.3-2-cachyos
6.12.43-3.1-cachyos-lts

Kernels that still show the problem (internet working very poorly):

6.16.3-arch1-1
6.12.43-1-lts

So it looks like some recent kernels (Nobara, CachyOS) already include
a patch that fixes the issue.
Could someone point me to which commit might be responsible for this
fix? That would help me apply it on Arch Linux as well.

Thanks a lot for your help

El mar, 26 ago 2025 a las 20:12, Eric Dumazet
(<eric.dumazet@gmail.com>) escribió:
>
>
> On 8/26/25 10:59 AM, Luis Alberto wrote:
> > Hi everyone, I’m new to this mailing list.
> >
> > I am reporting a network regression observed on my system when
> > upgrading from Linux kernel 6.16.1 to 6.16.2 (and persisting in
> > 6.16.3). The issue affects both Wi-Fi and Ethernet interfaces and
> > seems to originate in the kernel networking stack rather than any
> > specific driver.
> >
> > For reference, I initially reported this issue on Bugzilla, ID 220484,
> > thinking it was exclusively a Wi-Fi problem.
> > Subsequent testing with a wired Ethernet connection confirmed that the
> > issue affects both interfaces.
> >
> > System / hardware information:
> > - Motherboard: Asus TUF GAMING B460M-PLUS (WI-FI)
> > - CPU: Intel i5-10400
> > - 16GB RAM
> > - GPU: NVIDIA 4060 (proprietary open module drivers installed v580)
> > - Wi-Fi: Intel AX200, driver: iwlwifi + mac80211
> > - Ethernet: Intel I219-V, driver: e1000e
> > - Connections use IPv4
> >
> > Kernel versions tested:
> >    6.15.7, 6.15.8 and 6.16.1 (works fine)
> >    6.16.2 and 6.16.3 (regression present)
> >    LTS 6.12.43 from Aug 20 (regression present)
> >
> > Symptoms:
> > - Internet connectivity is intermittent: when opening multiple
> > websites simultaneously (e.g., 10 pages), roughly 1/4 fail to load.
> > - Failed pages either remain completely blank with a connection error
> > or load partially; both situations occur frequently.
> > - The issue also occurs occasionally with a single webpage, or when
> > downloading system updates, not limited to the browser.
> > - Occurs on both Wi-Fi and wired Ethernet.
> > - No connection drops; the interface remains "up".
> > - Tested in more than one distro: EndeavourOS and Nobara, vanilla installations.
> > - Ping comparison:
> >    6.16.2+: Running ping google.com while opening 10 webpages
> > successively results in >10% packet loss and several pages failing to
> > load.
> >    6.16.1: 0% packet loss and all pages load correctly on first
> > attempt, consistently.
> >
> > Actions taken:
> > - Opened a Bugzilla report, ID 220484, including dmesg, journal, and
> > tcpdump logs.
> > - Tested with both Wi-Fi and Ethernet; issue persists on both.
> > - Verified IPv4 usage; IPv6 is link-local only.
> > - Tested repeatedly on kernel 6.16.1 and earlier: everything works perfectly.
> >
> > Reproduction steps:
> > 1. Boot kernel 6.16.2 or 6.16.3
> > 2. Connect via Wi-Fi or Ethernet
> > 3. Attempt to load multiple websites
> > 4. Observe inconsistent traffic and intermittent failures
> >
> > Any help is much appreciated.
> >
> > Could anyone advise which commits between 6.16.1 and 6.16.2 might have
> > introduced this behavior, or suggest any testing and further steps?
> >
> > Thank you very much.
> >
> > Best regards,
> > Luis Alberto
>
>
> Please try :
> https://lore.kernel.org/all/20250821105806.1453833-1-wangzijie1@honor.com
> <https://lore.kernel.org/all/20250821105806.1453833-1-wangzijie1@honor.com>
>
>
> >

Fwd: [BUG] Network regression on Linux 6.16.1 -> 6.16.2 (persists in 6.16.3): intermittent IPv4 traffic on Wi-Fi and Ethernet

[Luis Alberto]

Hi all,

Forwarding some relevant links shared by Damien Wyart that seem
directly related to the network issue I’m experiencing.

Many thanks to Damien and everyone contributing to tracking this down!

Links:

https://discuss.cachyos.org/t/internet-issues-following-last-system-upgrade/14123
https://bbs.archlinux.org/viewtopic.php?id=307778
https://lore.kernel.org/regressions/20250822165231.4353-4-bacs@librecast.net/