Hi, I am trying to have the following, simple implemented in other devices scenario:
Port 1 Native VLAN 11
Port 1 VLAN 302 tagged

Port 2 VLAN 11 tagged
Port 2 VLAN 302 tagged

I dont have any problem with Port 2, but for Port 1 I can have only the one or the other VLAN playing with "always strip" or "leave as is". Any ideas?

I had the same problem, it seems that there is no possibility to make RB250 not tag default vlan, it is possible to set it "leave as is" but it works only if packets are already properly tagged.