I am on wireless. Does it matter?
Yes, it does. If you follow that tutorial, you'll end up arp poisoning the whole network, since you're not specifying targets. Your wireless adapter won't be able to receive and forward all the packets to their correct destination, causing slow connection on the victims, or even DoS. From previous experience, I can say you can arp poison one host + gateway at a time while using wireless adapters, and even then, the victim's connection will slow down a bit. With wired connection, I've never had any problems. I once arp poisoned a whole network (10 hosts) and everything went well. No DoS, no slow connection on the victims, every packet passed trough my computer without any problem.
If you're using wireless, and in order to limit your targets, once you get to the hosts window, just select a host and click on "Add to target 1" and then select the gateway and click on "Add to target 2".
