VLAN config on second switch via trunk — SOM + SwitchBlox Rugged

Hi all,

I have the following hardware setup:

  • 1x Rugged SOM (BB-SOM-A-1) stacked on 1x SwitchBlox Rugged (BB-SWR-G-1) — running OpenWRT

  • 1x second SwitchBlox Rugged (BB-SWR-G-1) connected to Switch 1 via a trunk link (PicoBlade → RJ45 coupler → RJ45 → PicoBlade)

  • 1x Arduino (Rugged MEGA) connected to a port on Switch 1

  • 4x identical devices connected one per port on Switch 2

  • External ethernet uplink into Switch 1

My goal:

  • Assign each port on Switch 2 to its own VLAN (VLAN 10, 20, 30, 40) to identify which device is talking, since all 4 devices run identical firmware and send to the same multicast address

  • Have the SOM route each VLAN’s traffic to a unique IP so the Arduino can identify which device it’s receiving from

  • The trunk link between Switch 1 and Switch 2 carries all 4 VLANs tagged

Questions:

  1. How do I configure the trunk port on Switch 1 in OpenWRT to carry VLANs 10/20/30/40 tagged to Switch 2?

  2. How do I assign each port on Switch 2 to its respective VLAN from the SOM — does Switch 2 appear as additional lan interfaces in OpenWRT?

  3. What is the recommended way to route VLAN 10 → 192.168.10.x, VLAN 20 → 192.168.20.x etc. so the Arduino sees each device on a distinct IP?

Current ifconfig output shows br-lan on lan1-lan4 with lan5 as WAN. Basic connectivity is working, I can ping the SOM at 192.168.2.1.

Any help appreciated, attaching a diagram.