我が家はデスクトップはiMacのみで、モニターやキーボードを準備するのが面倒なのでRaspberryPiのセットアップはいつもヘッドレスで行っています。
sshファイルとwpa_supplicant.confの設定してbonjourかarpの一覧表示でIPを調べられます。
RC211v-mbp:Downloads dp$ ping raspberrypi.local
PING raspberrypi.local (192.168.1.39): 56 data bytes
64 bytes from 192.168.1.39: icmp_seq=0 ttl=64 time=3.794 ms
64 bytes from 192.168.1.39: icmp_seq=1 ttl=64 time=3.411 ms
^C
--- raspberrypi.local ping statistics ---
2 packets transmitted, 2 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 3.411/3.603/3.794/0.192 ms
RC211v-mbp:Downloads dp$
RC211v-mbp:Downloads dp$arp -a
? (169.254.118.171) at b8:27:eb:97:d6:6d on en0 [ethernet]
? (192.168.1.1) at e4:7e:66:34:1b:58 on en0 ifscope [ethernet]
? (192.168.1.6) at (incomplete) on en0 ifscope [ethernet]
? (192.168.1.7) at (incomplete) on en0 ifscope [ethernet]
? (192.168.1.8) at (incomplete) on en0 ifscope [ethernet]
? (192.168.1.9) at 18:65:90:d0:51:5 on en0 ifscope permanent [ethernet]
? (192.168.1.10) at (incomplete) on en0 ifscope [ethernet]
? (192.168.1.11) at (incomplete) on en0 ifscope [ethernet]
? (192.168.1.12) at f0:81:73:98:aa:5b on en0 ifscope [ethernet]
? (192.168.1.13) at (incomplete) on en0 ifscope [ethernet]
? (192.168.1.14) at (incomplete) on en0 ifscope [ethernet]
? (192.168.1.15) at (incomplete) on en0 ifscope [ethernet]
? (192.168.1.16) at (incomplete) on en0 ifscope [ethernet]
? (192.168.1.22) at 7c:61:66:da:d7:41 on en0 ifscope [ethernet]
? (192.168.1.39) at b8:27:eb:97:d6:6d on en0 ifscope [ethernet]
? (192.168.1.255) at ff:ff:ff:ff:ff:ff on en0 ifscope [ethernet]
? (224.0.0.251) at 1:0:5e:0:0:fb on en0 ifscope permanent [ethernet]
? (239.255.255.250) at 1:0:5e:7f:ff:fa on en0 ifscope permanent [ethernet]