Canon iR C6800 Series Service Manual page 1280

Chapter 15
If the machine indicates 'NG', suspect a fault in the TCP/IP settings of the machine; go back to step 3),
and check the settings.
If the machine indicates 'OK', the TCP/IP settings of the machine are likely to be correct. Suspect, on
the other hand, a fault in the connection of the network interface board (NIC) or the board itself. Go on
to step 7).
* A loopback address will return before it reaches the NIC, offering a means to check the TCP/IP
settings of the machine itself.
7) Make the following selections in service mode: COPIER>TEST>NETWORK>PING. Then, enter
the local host address (IP address of the machine), and press the OK key.
If the machine indicates 'NG', suspect a fault in the connection of the NIC or the NIC itself. Check its
connection, or replace it as necessary.
If the machine indicates 'OK', the network settings of the machine and the NIC are likely to be correct.
Suspect a fault in the user's network environment; ask the system administrator for corrective action.
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