However, the ethertype is reflecting the port:-
lan1/5 : ethertype Unknown (0xc028), length 176:
lan2/7 : ethertype Unknown (0xc038), length 176:
lan3/0 : ethertype Unknown (0xc000), length 176:
lan4/1 : ethertype Unknown (0xc008), length 176:
wan/2 : ethertype Unknown (0xc010), length 176:
My other one of these routers, running OpenWRT / Linux 3.3.8, shows
the same ethertypes, which suggests that the switch is still in DSA
tagging mode. I'll poke around further and see what I find.
O.K. With this wrong, nothing is going to work.
I will check that the 6131 actually supports EDSA!
Andrew