TL;DR: On NVIDIA/Mellanox switches running Cumulus Linux, list existing VLANs with nv config show, add a new VLAN with nv set bridge domain br_default vlan <id>, then apply and save the configuration so it survives a reboot.

Recommended action:

  1. Connect to the switch console (or SSH in as the cumulus user) and review the current configuration:

    nv config show

    Look under bridge → domain → br_default → vlan for the list of VLAN IDs already trunked on the bridge.

  2. Add the new VLAN to the default bridge domain. Replace XXX with the VLAN ID you want to add (for example, 60):

    nv set bridge domain br_default vlan XXX
  3. Apply the pending change to the running configuration:

    nv config apply
  4. Persist the change so it survives a reboot:

    nv config save
  5. Repeat the same sequence on the second switch in the pair so both peers carry the new VLAN identically.

Why:

NVIDIA Cumulus Linux uses NVUE (nv commands) to manage configuration. Adding a VLAN to br_default makes it available across all bridge member ports — i.e., the trunks between switches and the server-facing links that are members of the default bridge. nv config apply activates the change in the running config, but only nv config save writes it to startup configuration; without the save step, the VLAN disappears on the next reboot.

Going forward:

Always run nv config show first to see the existing VLAN list before adding — this avoids reusing an ID that's already trunked. Apply and save on both switches in a redundant pair within the same maintenance window so they stay in sync. After the change, validate from a host on the new VLAN that it can reach its expected gateway/peers.

Optional details:

If a port should carry only specific VLANs rather than every VLAN on br_default, you can scope membership at the interface level (nv set interface swpX bridge domain br_default ...). For most server-facing access/trunk scenarios on a DataON-shipped pair, adding the VLAN to the bridge domain is sufficient because the server links are already members of br_default.