Debug ARP requests

Hello everyone,

I have a problem:
My client-pc (connected via eth0) makes an arp-request to the router.The PC wants to know the mac address of an device which is connected via wwan0.
I am able to see the the mac-address in the arp-table (via "arp" or "ip neigh") so i am sure the router knows the mac address.

i now turned on proxy_arp with "echo 1 > /proc/sys/net/ipv4/conf/eth0/proxy_arp"

so normaly the router would answer to the arp-requests. BUT IT DOES NOT, and it drives my crazy.

is there a way to debug arp on the router (lede)?
i think it sends out the arp-answer to an wrong interface but im not quite sure.

thank you

ok, i now made a tcpdump, and i see that the lede-device is not answering at all.

but why? :frowning: