realtek: Traffic directly on lanX not working

[Birger Koblitz]

Hi,

On 19.06.21 14:25, Hauke Mehrtens wrote:
> Hi,
> 
> I am unable to send and receive packets directly on the lan1 interface when it is not part of a bridge.
> 

> In wireshark on a connected host I do not see any packets from this device, but the link is up.
> 
> When I use OpenWrt's default network configuration using a bridge, network works like expected.
> I took care of the VLAN 100 which is used by default, but this setup does not use any VLAN.
> 
> I would like to use a very similar configuration for the failsafe mode which is also not working correctly.

This is the same finding tmon had:
https://forum.openwrt.org/t/support-for-rtl838x-based-managed-switches/57875/598

The reason is a hardware limitation on RTL chip families 8380-9300, they require a port to be a member of VLAN 1
in order to send/receive traffic:
https://forum.openwrt.org/t/support-for-rtl838x-based-managed-switches/57875/602

I am not sure how to proceed. One solution is to set this up silently in the driver, but then the existence of
vlan 1 would be intransparent to the user, a possible security risk.

Birger