### Describe the issue you are experiencing
After upgrading from HAOS 17.3 to 1…8.0, my Raspberry Pi 5 started experiencing continuous ethernet link flapping every ~6-10 seconds. dmesg shows a repeating pattern:
```
macb 1f00100000.ethernet end0: Link is Down
macb 1f00100000.ethernet end0: Link is Up - 1Gbps/Full - flow control off
```
This causes system-wide sluggishness (5-10s input freezes) and all network-dependent integrations intermittently losing connectivity.
I also tested HAOS 18.1 (including the updated RPi 5 firmware) — same issue persists.
Rolling back to HAOS 17.3 (kernel 6.12) immediately resolves the problem each time. The new RPi 5 firmware has no issues with 17.3.
**Troubleshooting steps that did NOT resolve the issue:**
- Replaced ethernet cable
- Tried different router port
- Restarted router
- Restarted Home Assistant and the Pi multiple times
**Note:** I'm aware that other Pi 5 users are not experiencing this, so this may be specific to my hardware combination or board revision. Posting this to help track down what's different.
### What operating system image do you use?
rpi5-64 (Raspberry Pi 5 64-bit OS)
### What version of Home Assistant Operating System is installed?
18.1
### Did the problem occur after upgrading the Operating System?
Yes
### Hardware details
**Hardware setup:**
- Raspberry Pi 5 Model B Rev 1.1, 8GB
- SunFounder Pironman 5 case (active cooling, NVMe M.2 slot) — ethernet plugged directly into the Pi, not through the case
- Official Raspberry Pi 5 power supply
- Connected directly to the main router (no switch in between)
### Steps to reproduce the issue
1. Start with a Raspberry Pi 5 Model B Rev 1.1 (8GB) running HAOS 17.3 — ethernet link is stable
2. Upgrade to HAOS 18.0 (or 18.1) via ha os update
3. After reboot, run dmesg | grep "Link is"
4. Observe continuous link flapping every ~6-10 seconds:
macb 1f00100000.ethernet end0: Link is Down
macb 1f00100000.ethernet end0: Link is Up - 1Gbps/Full - flow control off
5. Roll back to HAOS 17.3 via ha os update --version 17.3
6. After reboot, run dmesg | grep "Link is" — only a single "Link is Up" at boot, no further flapping
### Anything in the Supervisor logs that might be useful for us?
```txt
The flapping is at the kernel/driver level (dmesg), not the Supervisor level.
[ 2098.493260] macb 1f00100000.ethernet end0: Link is Down
[ 2103.618858] macb 1f00100000.ethernet end0: Link is Up - 1Gbps/Full - flow control off
[ 2109.757788] macb 1f00100000.ethernet end0: Link is Down
[ 2113.855293] macb 1f00100000.ethernet end0: Link is Up - 1Gbps/Full - flow control off
[ 2123.070366] macb 1f00100000.ethernet end0: Link is Down
[ 2126.143830] macb 1f00100000.ethernet end0: Link is Up - 1Gbps/Full - flow control off
[ 2133.310821] macb 1f00100000.ethernet end0: Link is Down
[ 2137.408329] macb 1f00100000.ethernet end0: Link is Up - 1Gbps/Full - flow control off
[ 2142.531358] macb 1f00100000.ethernet end0: Link is Down
[ 2146.625750] macb 1f00100000.ethernet end0: Link is Up - 1Gbps/Full - flow control off
[ 2152.767681] macb 1f00100000.ethernet end0: Link is Down
[ 2155.841150] macb 1f00100000.ethernet end0: Link is Up - 1Gbps/Full - flow control off
[ 2166.080318] macb 1f00100000.ethernet end0: Link is Down
[ 2171.201856] macb 1f00100000.ethernet end0: Link is Up - 1Gbps/Full - flow control off
[ 2178.368848] macb 1f00100000.ethernet end0: Link is Down
[ 2183.490424] macb 1f00100000.ethernet end0: Link is Up - 1Gbps/Full - flow control off
[ 2200.897897] macb 1f00100000.ethernet end0: Link is Down
[ 2203.971361] macb 1f00100000.ethernet end0: Link is Up - 1Gbps/Full - flow control off
[ 2212.162418] macb 1f00100000.ethernet end0: Link is Down
[ 2215.235882] macb 1f00100000.ethernet end0: Link is Up - 1Gbps/Full - flow control off
```
### Anything in the Host logs that might be useful for us?
```txt
See dmesg logs
```
### System information
_No response_
### Additional information
```
## System Information
version | core-2026.7.0
-- | --
installation_type | Home Assistant OS
dev | false
hassio | true
docker | true
container_arch | aarch64
user | root
virtualenv | false
python_version | 3.14.6
os_name | Linux
os_version | 6.12.75-haos-raspi
arch | aarch64
timezone | Europe/Zurich
config_dir | /config
<details><summary>Home Assistant Cloud</summary>
logged_in | false
-- | --
can_reach_cert_server | ok
can_reach_cloud_auth | ok
can_reach_cloud | ok
</details>
<details><summary>HACS</summary>
GitHub API | ok
-- | --
GitHub Content | ok
GitHub Web | ok
HACS Data | ok
GitHub API Calls Remaining | 4995
Installed Version | 2.0.5
Stage | running
Available Repositories | 3459
Downloaded Repositories | 24
</details>
<details><summary>Home Assistant Supervisor</summary>
host_os | Home Assistant OS 17.3
-- | --
update_channel | stable
supervisor_version | supervisor-2026.06.2
agent_version | 1.8.1
docker_version | 29.3.1
disk_total | 234.0 GB
disk_used | 54.1 GB
nameservers | 192.168.1.10, 2001:1715:9d93:1081:1535:7291:b56f:1d19
healthy | true
supported | true
host_connectivity | true
supervisor_connectivity | true
ntp_synchronized | true
virtualization |
board | rpi5-64
disk_life_time | 4 %
supervisor_api | ok
version_api | ok
installed_addons | Studio Code Server (6.0.1), Zigbee2MQTT (2.12.1-1), Mosquitto broker (7.1.0), Advanced SSH & Web Terminal (24.0.1), ESPHome Device Builder (2026.6.4), Node-RED (22.0.0), Grocy (0.25.1), Claude Terminal (2.2.2), AppDaemon (0.18.5), Home Assistant Google Drive Backup (0.112.1), motionEye (0.23.0), Pi Config Wizard (1.0.3), Pironman 5 (1.2.6), HDD Tools (1.1.0), Tailscale (0.28.1), Puppet (2.5.0)
</details>
<details><summary>Dashboards</summary>
dashboards | 13
-- | --
resources | 15
views | 44
mode | storage
</details>
<details><summary>Network Configuration</summary>
adapters | lo (disabled), end0 (enabled, default, auto), hassio (disabled), docker0 (disabled), veth3c843ef (disabled), veth9eaac73 (disabled), veth243ae54 (disabled), veth4e9ecf5 (disabled), vethcb97371 (disabled), veth509b543 (disabled), vethfb944ef (disabled), veth5bea447 (disabled), veth856555f (disabled)
-- | --
ipv4_addresses | lo (127.0.0.1/8), end0 (192.168.1.11/24), hassio (172.30.32.1/23), docker0 (172.30.232.1/23), veth3c843ef (), veth9eaac73 (), veth243ae54 (), veth4e9ecf5 (), vethcb97371 (), veth509b543 (), vethfb944ef (), veth5bea447 (), veth856555f ()
ipv6_addresses | lo (::1/128), end0 (fdb0:2e49:755f:0:8b2e:a73e:7d4c:b977/64, fe80::b64f:be1a:62c0:23a4/64), hassio (fd0c:ac1e:2100::1/48, fe80::70c7:ebff:fe1c:4bb2/64), docker0 (fd7a:621d:e79e::1/64, fe80::d80a:6cff:fe9d:8c2c/64), veth3c843ef (fe80::8877:e7ff:fe58:a377/64), veth9eaac73 (fe80::cb7:7ff:fed1:bab7/64), veth243ae54 (fe80::e406:c4ff:fe4b:6cb4/64), veth4e9ecf5 (fe80::c033:1cff:fe6d:e926/64), vethcb97371 (fe80::d868:7cff:fe57:bd93/64), veth509b543 (fe80::59:b6ff:fe37:929a/64), vethfb944ef (fe80::5cf8:fff:fe96:f9cc/64), veth5bea447 (fe80::c067:ceff:fe6d:31a7/64), veth856555f (fe80::90aa:4dff:fe9b:5ee/64)
announce_addresses | 192.168.1.11, fdb0:2e49:755f:0:8b2e:a73e:7d4c:b977, fe80::b64f:be1a:62c0:23a4
</details>
<details><summary>Recorder</summary>
oldest_recorder_run | December 20, 2025 at 10:08 AM
-- | --
current_recorder_run | July 2, 2026 at 10:12 AM
estimated_db_size | 9100.23 MiB
database_engine | sqlite
database_version | 3.53.2
</details>
```