Find machine on network
# all known hosts
arp -a
# find by name (may need to install awahi)
dig +short @224.0.0.251 -p 5353 raspberrypi.local
# brute force (ping all ips in local network)
hostname -I # find network adress, i.e 192.168.1.123
nmap -sn 192.168.1.0/24