Publishing an ARP entry

I'm experimenting with a spoofed IP connection, as described in section 7 of this article (IP SPOOFING with BSD RAW SOCKETS INTERFACE ). Indeed, when a SYN is sent with no regard for ARP, there's no response. One of the two solutions presented in the article (should be the simpler) is to add a static ARP entry to the client host. My host is configured as 10.1.1.10 and I want the spoofed IP address to be 10.1.1.20. To add the new entry, I ran: # arp -i enp4s2 -Ds 10.1.1.20 enp4s2 pub and when I run arp -n, it shows: 10.1.1.20 * * MP enp4s2 From the server, I tried to arping 10.1.1.20 and there is no reply from the client host (with the published ARP entry). Probably I didn't understand how ARP publishing works. Literature on the net seems to be very simplified on this matter. My distro is an OpenSuSE and the kernel version is 3.16.7-21-desktop #1 SMP PREEMPT.