Hello Dear Sven:
there are /a clerical/ //error// about batctl nc and i compiled the part .
run these command in according to advisement for relay mode
batctl nc 1 echo 1 > /sys/class/net/bat0/mesh/network_coding ip link set dev wlan0 promisc on ip link set dev wlan0 mtu 1546
if i send a packet from host A to hostC via hostB, whether hostB will open relay mode at layer2 .
Best Regards
TIger