ARP and NS offload in suspend and off


Jan 24, 2024
Is there a way to enable ARP and NS offload to the NIC, especially in off or suspend mode?

I use a forwarded port to send the UDP packets to my truenas machine. My issue is that I cannot wake it from the internet as soon as my router removes the arp entry. If truenas is running I can check that the packets are delivered by running
tcpdump -v -i enp4s0 ether proto 0x0842 or udp port 7
If I am quick and send a packet as soon as the machine has finished shutting down it will wake up. After a minute or so it will not.

A WOL broadcast in the same subnet will always wake the machine.

To verify that it has nothing to do with the hardware capabilities I ran a windows 2 go stick on the same machine. If I enable ARP and NS offload as well as WOL, wakeup worked from any state . I have been using this method for waking up various Windows machines for years. As long as windows fast startup is disabled and the machine is shut down properly it will even wake from off state.

I did some research but I could not really find much regarding ARP or NS offload under Linux.

I know my way around Linux but I am no expert. Maybe someone here can give me some insights in what to do or where to look.

Another solution would be to add a static arp entry to the router but it does not allow that. I contacted support but my hopes are slim.

The NIC is a i226-v integrated on an Asus B760-I board, the Router is a Fritzbox 7350.