how would configuring DNS even work without having to see the addresses, and how would SSH'ing to a device on the LAN work without seeing the addresses
NetBIOS/WINS protocol could discover names -> IPs by broadcast, more modernly Zeroconf/Bonjour can do it, and if there's some organization then DHCP servers can register hostnames in DNS when handing out addresses.
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how would configuring DNS even work without having to see the addresses, and how would SSH'ing to a device on the LAN work without seeing the addresses