Back in the day, you used to be able to connect to services bound to 127.1 on host A from host B by deleting 127.1 on host B, then adding a manual route to host

Back in the day, you used to be able to connect to services bound to 127.1 on host A from host B by deleting 127.1 on host B, then adding a manual route to host A's public IP. Host B stack sees packet for 127.1, says not me, routes it to host A, host A gets packet, looks at its IPs, sees 127.1, says oh this must be for me. Most systems are probably better about configuring host A to not let this happen now.