Hi, I'm having a bit of a weird issue.

I am running Kali Linux in dual boot with Windows 8.1 on a Lenovo ThinkPad Edge E520 laptop. I had an issue when installing Kali, where it couldn't find the firmware files for both wired and wireless network. I am not sure which wired device I have, but I'm using the built-in wireless device, which is an Intel Centurion Wireless-N 1000. After installing, I could connect to my wireless network without problems, but with no internet connection, so I picked up the iwlwifi-1000-3.ucode file and replaced the standard iwlwifi-1000-5.ucode in /lib/firmware. Still no connection. Then I compared the ifconfig output with the DHCP information from my router's administration page, and noticed that ifconfig returned the local IP 192.168.1.3 on eth0 (which isn't in use at all), and 192.168.1.2 on wlan0, while the router informed me that this MAC address was given the IP 192.168.1.2. So, just for giggles, I did an ifconfig eth0 192.168.1.2, and voila - I had internet!

I opened up /etc/network/interfaces and noticed that the IP on eth0 was set to 192.168.1.3 as well. I changed it to 192.168.1.2 as it should be, and rebooted: internet gone again. ifconfig revealed that the eth0 IP was now 192.168.1.2, though, so I changed it to 192.168.1.3 and then back, and the internet worked again. This is the procedure I have to follow after each reboot for my internet connection to work.

So now my question is.. How do I fix this permanently, so I don't have to do an ifconfig after every reboot? Not that I can't do that, but I'd rather not if it can be done.

Many thanks in advance!