The Psiber Pinger is a unique handheld tester used for installing and maintaining computer Local Area Networks (LANs) running the TCP/IP protocol. The Pinger uses the powerful Ping function to verify connectivity, check transmitted and received data integrity, indicate network traffic loading by measuring round trip time, notify duplicate IP address responses, provide the MAC address of an IP address and warn when the default gateway cannot be located. The Pinger also identifies reversed polarity for improperly connected wire pairs and provides a port identification feature with selectable blink rates to identify which port on a hub or switch a wall outlet is connected.