Recently I became interested in sniffing/spoofing. I'm running Kali Linux with MITMf(9.8) and SSLstrip.

To start the attack I use:

    python mitmf.py -i wlan0 --target X.X.X.2 --gateway X.X.X.1 --arp --spoof --hsts

1. Victim I(OS X)

I tried to attack my MBP. It works. I can sniff username/passwords when it connects to http sites. It doesn't last long though. After a minute or so my connection on the victim machine is completely dead. I have to stop the attack and reconnect the victim machine to the router to make it's internet connection work again.

I thought it might have been caused by having IP forwarding disabled, but as it turns out it works even worse when it's enabled (connection is lost on victim's machine almost immediately).

Then, I thought it might be an issue with my router, so I tried to run a hotspot on my iPhone. Indeed, it improved the length of the attacks greatly, but still after 2-3 minutes the connection died on the victim's machine.

What can be causing this?

2. Victim II (Bootcamp Windows 8.1 Pro)

My second Victim was a Windows 8.1 machine running in bootcamp. No luck here either. The connection is killed immediately after I run MITMf command.

Has anyone encountered these issues?