Network device with testing of forwarding rules using tunneling

A method, comprising:

• in a network device, performing a first lookup on a probe network packet using a first destination address, the first lookup for determining a first port on which to transmit the probe network packet;
• performing a second lookup using a second destination address associated with a testing system associated with testing the network device, the second lookup for determining a second port on which to transmit the probe network packet;
• rewriting the probe network packet in accordance with the first lookup;
• encapsulating the rewritten probe network packet using results of the second lookup to generate an encapsulated packet that includes the rewritten probe network packet;
• and
• transmitting the encapsulated packet on the second port.

An Integrated Circuit (IC), comprising:

• layer 3 circuitry for performing a lookup on a probe network packet for determining a first port to which the probe network packet is to be transmitted, wherein the layer 3 circuitry rewrites the probe network packet in accordance with the lookup;
• probe detection circuitry for determining that the probe network packet is a probe;
• circuitry for reading a register that stores a network address where test results are to be transmitted, the network address for use in a lookup in the layer 3 circuitry for determining a second port;
• and
• circuitry for encapsulating the rewritten probe network packet in a test results packet and for transmitting the test results packet on the second port.