Before starting make sure your Kali & Butler machines are on the same network. Butler should be configured with DHCP. To find the IP address lets use arp-scan.
arp-scan -l
Interface: eth0, type: EN10MB, MAC: 00:0c:29:b6:2b:dd, IPv4: 192.168.100.254
Starting arp-scan 1.10.0 with 256 hosts ...