Why does internet get disconnected after I change mac in Kali Linux?

Question

I have written this script to change my mac in Kali Linux:

ifconfig eth0|grep HWaddr
ifconfig eth0 down&&macchanger -r eth0&&ifconfig eth0 up
ifconfig eth0|grep HWaddr

The problem is each time I do this internet gets disconnected even though I am doing ifconfig eth0 up after changing mac. Then I have to go to the double computer icon and open the drop down menu to click on Wired Connection 1 to reconnect to internet. Why is this happening? What command do I need to add to this script to reconnect to internet without using GUI?

Solution 1

I figured it out (dont know if it works for virtual machines):

1. $ifconfig eth0 down and/or ifconfig wlan0 down
2. $service network-manager stop
3. $macchanger -r eth0 and/or macchanger -r wlan0
4. $service network-manager restart

note: i dont turn the ifconfig wlan0 or eth0 up, because when you restart the network manager they work, but in case it turn them up manually with ifconfig eth0 up or some jazz like that it doesnt work for me. you can check that both network interfaces work by typing $ifconfig (you can also see your new random MAC address).

$ - means the coding started eth0 - network interface wlan0 - network interface macchanger - alters the MAC address ifconfig - you should know that

Solution 2

It is the equivelant of disabling the inet device like so

$ ifconfig eth0 down

Then changing the hwaddr property to something else and bringing the device back online like so

$ ifconfig eth0 up