Canon MX490 series Online Manual page 592

When Encryption Is Enabled, Cannot Communicate with the Machine
after the Encryption Type Was Switched on the Wireless Router
If the machine cannot communicate with the computer after the encryption type of the machine was
switched, make sure that encryption types for the computer and the wireless router matches that set to
the machine.
Cannot Communicate with the Machine after Applying MAC/IP Address Filtering or Entering an
Encryption Key to the Wireless Router
592