Alright that looks good.
Have you analyzed with wireshark?
Oke so after you started the attack on your client go to the client machine and check the output of the command arp
Now Ill assume you now what it is supposed to say.
If it doesnt it somehow doenst get poisioned.
Here is the thing, I can only ssh into the Ubuntu computer. It is basically a virtual machine that is used primarily for security purposes that I am only allowed to interact with via a ssh. As such, I can't use wireshark or any other kind of GUI to aid me in this. Anyway, after I run those two arp commands I posted, I ran arp on the victim machine, but it didn't return anything (it stalled, so it wasn't doing anything). I also ran it on the machine performing the attack, and it returned the same thing it returned when I ran "arp" before I did the attack, which was the following (spacing may be off):
Address HWtype HWaddress Flags Mask Iface
cisco ether ADDRESS C eth0
VICTIM_IP_ADDRESS ether ADDRESS C eth0
OTHER_IP_ADDRESS ether ADDRESS C eth0