The 'arp -a' command lists the ARP cache entries, which can be scrutinized for duplicate MAC address assignments to determine if an address duplication conflict exists. This would align with the symptoms of sporadic connection loss that could occur if two devices are trying to use the same network address. On the other hand, using 'ping' or 'tracert/traceroute' would not reveal address duplication, as these commands focus on reachability and the path packets take, respectively. 'ipconfig /all' or equivalent commands simply list the interface configurations without revealing any direct evidence of duplicated addresses.