How to config 88E6176 switch on TURRIS MOX C?

MOX C got a 88E6176 switch, but there is no config entry both foris web or luci web.
Any clue?

Foris does not provide switch conf in general and LuCI has no support for it, that is since the driver been switched to DSA in TOS4.x (OpenWrt 18.x)

very informative. I subscribed the thread of the issue.
so whats the direction to solve the DSA config issue? command set “ip” or “bridge vlan”?

reached the conclusion that

ip l a l ${interface name} n ${virtual interface}.{name} type vlan id {VID}

is inhibited to just enabling (and in reverse disabling) 802.1q with tag state only but lacks advanced management of 802.1q.
vlan - 802.1q tagged virtual LAN interface

VLAN Type Support

    reorder_hdr { on | off } - specifies whether ethernet headers are reordered or not.
    gvrp { on | off } - specifies whether this VLAN should be registered using GARP VLAN Registration Protocol.
    mvrp { on | off } - specifies whether this VLAN should be registered using Multiple VLAN Registration Protocol.
    loose_binding { on | off } - specifies whether the VLAN device state is bound to the physical
    device state.
    ingress-qos-map QOS-MAP - defines a mapping between priority code points on incoming frames.
    The format is FROM:TO with multiple mappings separated by spaces.
    egress-qos-map QOS-MAP - the same as ingress-qos-map but for outgoing frames.

LuCI supports/utilizes ip l which works well with upstream WAN Vlan tagging, e.g. eth2.1

For advanced management of Vlan tagging on the downstream LAN (switch) ports it probably requires vlan filtering via the userland ip-bridge application.

It is not clear to me to which extent the governing DSA driver mv88e6xxx directly supports management of vlan tagging. From what I have been able to discern thus far it features certain registers that control certain functionality, e.g. register 7 for the ports is the default vlan tag register

to my understanding ip l is a membership semantic whilst vlan filtering is a packet switching semantic, different concepts.

Another consideration is whether involving userland, as opposed to driver, for Vlan tagging is as performant and perhaps more costly on the CPU.

Thanks, @n8v8r, it looks like you take a lot efforts on DSA config issue. Very appreciated. Do you happen to know if the kernel config option(CONFIG_BRIDGE_VLAN_FILTERING) enabled in next TOS4.0 beta version? And an ETA of DSA config?

you can check it on your node with zcat /proc/config.gz | grep VLAN

on my TOS5.x node it prints
# CONFIG_VLAN_8021Q_GVRP is not set
# CONFIG_VLAN_8021Q_MVRP is not set