2- Using NetworkManager: system-connections/Wired connection 1
root@kali:~# cd /etc/NetworkManager/system-connections/
root@kali:/etc/NetworkManager/system-connections# ls -al
total 20
drwxr-xr-x 3 root root 4096 Feb 19 09:18 .
drwxr-xr-x 6 root root 4096 Dec 2 18:52 ..
drwxr-xr-x 2 root root 4096 Dec 2 18:52 USRP
-rw------- 1 root root 170 Dec 2 21:24 Wired connection 1
-rw------- 1 root root 237 Feb 19 09:18 Wired connection 2
root@kali:/etc/network# more /etc/NetworkManager/system-connections/Wired\ connection\ 1
[connection]
id=Wired connection 1
uuid=12f59685-4e48-4d06-a25a-ca13304bc388
type=802-3-ethernet
[802-3-ethernet]
[ipv4]
method=auto
[ipv6]
method=auto
ip6-privacy=2
root@kali:/etc/network# more /etc/NetworkManager/system-connections/Wired\ connection\ 2
[ethernet]
mac-address=08:00:27:43:76:40
[connection]
id=Wired connection 2
uuid=9f022778-7319-4e30-993f-8183fe6ff436
type=ethernet
timestamp=1455873378
[ipv6]
method=auto
[ipv4]
method=manual
address1=192.168.200.50/24,192.168.200.1