Diagnosis of a network adapter during network operation

A computer system including a built-in network interface chip for network testing, the computer system comprising:

• a mainboard;
• a central processing unit directly connected to the mainboard,
• the central processing unit configured to host an application, the application configured to generate a network communication stream, the network communication stream containing a plurality of network packets for other computers and a network packet for the computer system;
• a network adapter driver configured to differentiate the network packet from the plurality of network packets by encoding the network packet with a first identifier;
• one or more first physical traces on the mainboard;
• the network interface chip directly connected to the mainboard, the network interface chip communicatively connected to the central processing unit by the one or more first physical traces, the network interface chip configured to receive the network communication stream from the central processing unit, the network interface chip further configured to route the network packet to a local loopback pathway away from the network and to the central processing device in response to the first identifier, wherein the local loopback pathway is entirely internal to the computer system;
• one or more second physical traces on the mainboard;
• and
• the network transceiver directly connected to the mainboard, the network transceiver communicatively connected to the network interface chip by the one or more second physical traces, a network transceiver configured to receive the plurality of network packets from the network interface chip, the network transceiver further configured to transmit the plurality of network packets to the network.