In a Mixed Virtual Chassis (VC) environment comprising heterogeneous platforms such as QFX5100 and EX4300, customers may observe errors during execution of the commit check command. However, the subsequent commit command completes successfully and the configuration is applied as expected.

This behavior is non-impacting and does not indicate a configuration syntax or semantic issue.

The issue may present with the following symptoms:

- Customer is running a Mixed Virtual Chassis consisting of QFX5100 and EX4300 switches (or other mixed switch models).

- commit check reports errors such as:

• invalid value
• error recovery ignores input until this point
• remote unlock-configuration failed on fpcX

- Despite the above, commit succeeds and the configuration is applied on all members.

Example Virtual Chassis Output

root> show virtual-chassis

Preprovisioned Virtual Chassis

Virtual Chassis ID: fffd.f05a.1699

Virtual Chassis Mode: Mixed

Member ID Status Serial No   Model       prio Role   Mode

0 (FPC 0) Prsnt  XXXXXXXXX  qfx5100-48s-6q   129  Backup  Y

1 (FPC 1) Prsnt  XXXXXXXXX  qfx5100-48s-6q   129  Master* Y

2 (FPC 2) Prsnt  XXXXXXXXX  ex4300-48t     0   Linecard Y

3 (FPC 3) Prsnt  XXXXXXXXX  ex4300-48t     0   Linecard Y

Example commit check Output

root# commit check

configuration check succeeds

fpc0:

configuration check succeeds

fpc2:

configuration check succeeds

fpc3:

configuration check succeeds

fpc2:

error: invalid value

error: error recovery ignores input until this point

fpc1:

error: remote unlock-configuration failed on fpc2

fpc3:

error: invalid value

error: error recovery ignores input until this point

fpc1:

error: remote unlock-configuration failed on fpc3

- In a Mixed Virtual Chassis, the commit check operation performs distributed configuration validation across all VC members. Due to platform heterogeneity (QFX and EX using different internal validation paths and feature sets):

• Platform-specific configuration (for example, QFX-specific interface or hardware attributes) is validated across all members.
• Linecard-only members (EX4300) may momentarily fail during configuration lock/unlock or validation phases.
• This results in false-positive validation errors during commit check.

- These errors occur during inter-member configuration database synchronization and do not represent invalid configuration syntax or logic.

This behavior is expected in Mixed Virtual Chassis environments and does not indicate a functional issue.

When executing commit, the following successful output is observed:

root# commit

configuration check succeeds

fpc0:

commit complete

fpc2:

commit complete

fpc3:

commit complete

commit complete

- Ensure all VC members are running the same Junos OS version.

- Please perform the below steps to clear the error. Perform commit synchronize or commit synchronize force and check if the error gets cleared:

SW@# commit synchronize

SW@# commit synchronize force

- If issue persists then you will need to reboot the members individually on which the error logs were seen:

Sw@> request system reboot member <member-id>