LAN wizard VLAN changes rewrite trunk port PVID, causing mgt loss

LAN wizard VLAN changes rewrite trunk port PVID, causing mgt loss

LAN wizard VLAN changes rewrite trunk port PVID, causing mgt loss
LAN wizard VLAN changes rewrite trunk port PVID, causing mgt loss
Yesterday
Model: TL-SG3428MP  
Hardware Version: V6
Firmware Version: 6.20.20 Build 20260113 Rel.67732

I've experienced three separate outages on my SG3428MP (hardware v6.20, firmware 6.20.20) caused by what appears to be the same bug fixed in firmware 6.30.1: "Fix the issue of IP loss caused by repeated modification of VLAN configuration by the controller."

 

Reproduction steps:

  1. Switch is adopted in Omada controller (v6.1.0.19), trunk uplink port configured with PVID=1 and tagged VLANs 10/100/152/153
  2. Use the Omada LAN network wizard (Network Config > LAN > Edit network) to add or remove a VLAN from any network
  3. The wizard rewrites the PVID on the trunk uplink port, stripping tagged VLANs from the allowed list
  4. Result: switch loses management connectivity, all APs drop off controller, WiFi stops passing traffic

 

Recovery required each time: serial console access (minicom at 38400 baud), manually re-adding the stripped VLANs via CLI, then reboot.

 

Observed three times: 21 Mar 2026, 22 Mar 2026, and 5 May 2026. The third incident also resulted in credential loss requiring boot menu password recovery and full switch re-adoption.

 

Workaround: avoid the LAN network wizard entirely; use switch port profiles instead.

I note that firmware 6.30.1 for the 6.30 hardware revision includes a bug fix that matches this behavior exactly. That fix does not appear in 6.20.22 (the current release for 6.20 hardware).

 

Could you confirm whether this is the same root cause, and whether a backport to the 6.20 firmware branch is planned?

 

Environment:

  • Switch: SG3428MP hardware v6.20, firmware 6.20.20 Build 20260113
  • Controller: Omada Software Controller v6.1.0.19 (Linux)
  • Confirmed reproducible via LAN wizard in both "add VLAN" and "remove VLAN" operations
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#1
3 Reply
Re:LAN wizard VLAN changes rewrite trunk port PVID, causing mgt loss
19 hours ago

  @LeadershipGeek Note: The third incident (5 May 2026) was triggered via the Omada mobile app, not the web controller UI. This suggests the issue is in the controller backend's VLAN provisioning logic rather than a web UI-specific behavior.

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#2
Re:LAN wizard VLAN changes rewrite trunk port PVID, causing mgt loss
10 hours ago

Hi  @LeadershipGeek 

 

Thanks for posting here.

 

We have released a new firmware update for your switch; the download link is below.

 

SG3428MP V6.20 V6.20.26

 

It has fixed some known issues. Please update it and let us know if the situation persists. Thanks.

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#3
Re:LAN wizard VLAN changes rewrite trunk port PVID, causing mgt loss
19 minutes ago

@Vincent-TP  Thank you for the response.

 

To clarify: I have reviewed the release notes for firmware 6.20.22 and the three bug fixes it contains do not address this issue.  I can confirm the 6.20.22 release notes contain no VLAN-related fixes. This is a matter of reading the documentation, not testing.

 

The fix that appears to match this behavior — "Fix the issue of IP loss caused by repeated modification of VLAN configuration by the controller" — is present in firmware 6.30.1 for the 6.30 hardware revision, but was not backported to the 6.20 branch in 6.20.22.

 

When this occurs, it crashes my entire home network, and I have to physically be present at the switch to recover.  This is a painful process.

 

 

I am willing to update to 6.20.22 and retest if that is required for your process, but based on the release notes I do not expect it to resolve the issue.

 

My question remains: is a backport of the 6.30.1 fix to the 6.20 firmware branch planned?

Must I really invest ANOTHER hour with my network down before you can answer my question?  The experience of dealing with this is AWFUL.

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#4