Applications / Canon Utilities / IJ Network Tool
.System Preferences > Printers & Scanners
.Applications / Canon Utilities / IJ Network Tool
....may not let you use all the features...
/Library
on the first Mac. Maybe its configuration had succeeded because it still had an old MX870 printer driver installed./Library/Printers/PPDs/Contents/Resources/CanonIJMX870series.ppd.gz
Canon MX870 Series
. I selected it.Applications / Canon Utilities / IJ Network Tool
to configure the device for use over WiFi.