BCM57414 25G NIC limited to 10G — bnxt_en driver not advertising 25G link modes

TrueNAS General
4

Quick update regarding this issue:

I opened a bug report with iXsystems and provided the collected information, debug data, reproducible behavior, and references to this thread. The report was closed with the conclusion that this is “not a TrueNAS bug”, although no technical explanation or additional context was provided.

JIRA reference: NAS-140993
URL: ixsystems.atlassian[.]net/browse/NAS-140993

I would appreciate some clarification on the reasoning behind that conclusion, because the behavior still appears strongly correlated with the upgrade itself and seems fully reproducible:

  • Same hardware

  • Same Broadcom BCM57414 NICs

  • Same DACs

  • Same Juniper QFX switches

  • Same LACP configuration

  • No network changes

  • No hardware changes

  • Only difference: Boot Environment / TrueNAS version

Behavior observed:

  • Boot 25.04.2.3 → interfaces negotiate and operate normally at 25Gb

  • Boot 25.04.2.6 → both interfaces fail simultaneously

  • Roll back to 25.04.2.3 → connectivity immediately restored

We also tried several troubleshooting actions without success:

  • Re-enabled autonegotiation manually

  • Adjusted FEC settings

  • Removed interfaces from the LACP bond

  • Restarted switch ports

  • Reviewed dmesg and journalctl

  • Verified no hardware, PCIe, firmware, or link-related errors

Since both interfaces fail simultaneously and immediately recover after reverting the Boot Environment, it still looks like some change between releases could be involved (kernel, bnxt_en, firmware package, PHY handling, networking stack behavior, etc.), even if the root cause is ultimately upstream.

If anyone has seen similar behavior with BCM57414 adapters, bnxt_en, Juniper QFX, DAC links, or newer TrueNAS versions (including 25.10.x), I would be very interested in hearing about your experience.

At this point, without additional clarification or understanding of the root cause, this issue effectively becomes a blocker for continuing TrueNAS upgrades on systems using BCM57414 adapters, since upgrading currently introduces a reproducible loss of 25Gb connectivity.

I’m also willing to schedule a maintenance window and temporarily boot back into 25.04.2.6 to collect additional diagnostics if someone can suggest specific data that may help narrow this down.