With the help of Canon's Telephone helpdesk, I have made som progress. I had several problems:
1) Because I had several interacting problems with the printer, I had changed lback and forth between wired and wireless connection for the printer. At one point, I had gotten some confusion between my iPhone and my network infrastructure devices relating to whether the printer was on WiFi or on the wired network. Power cycling the WiFi AP eventually resolved that,
2) Sorting out different layers of connectivity problem became easier when I got the "Canon PRINT" app from the App Store. Be careful not to also download the "Smart Print" app, which tries to attach itself to the download.
3) The ImageCLASS MF663CDw can only be attached one way at a time: Either to WiFi or to the Ethernet. You can print from your iPhone either with AirPrint or the Canon PRINT app, but both of them will only work over WiFi, not over wired Ethernet. It was easier for the support rep to work with the Canon PRINT app than with AirPrint.
4) The service rep thought that AirPrint should work through a WiFi access point. It appears that he was wrong.
5) I had it working while I was on the phone with the helpdesk. After I hung up, I decided to try it over a wired connection, and I never got it working again! I will call back on Monday!
