Automatic Macchanger & OpenVPN Killswitch?

[Stupendous]

I was curious if anyone knows how I can have a random (or pre-entered fake) MAC address assigned on kali startup as well as how I can block all traffic out/in my network while not connected to a VPN.

So far for macchanger, I have tried using init.d script to run macchanger -r in between putting wlan0 down/up which did not work and I believe the network manager may be interfering with the script working properly and am not sure how to do it. Any help would be much appreciated. Thanks in advanced.

[Stupendous]

Solved both of my questions, thanks anyways.

Solutions:
Macchanger on startup - in network manager interface add a "cloned address" inside the wlan/ethernet connection and it will connect with that as your MAC addeess.
VPN killswitch - installed ufw firewall (apt-get install gfuw) and added rules to deny all out/in by default and only allow outward to VPN IPs (to make connection) and in/out tun0 for internet connection while connected to VPN. Finally I allowed all in/out on all private IP networks for LAN communication (192.16.0.0/16,172.16.0.0/12,10.0.0.0/8) and in/out 255.255.255.255 for DHCP.