During a post-exploitation phase, you have a low-privilege shell on a dual-homed Linux host (eth0 on 10.10.10.0/24, eth1 on 172.16.5.0/24). You lack root and cannot install tools or run a network scanner. Before setting up a pivot, you want to quickly identify which hosts on the internal 172.16.5.0/24 segment this box has recently communicated with, without generating noisy new traffic. Which action best accomplishes this?