I'm about to perform an update for a client on a copy of their Moodle instance, bringing it up from Moodle 1.9 to 2.3. I'd forgotten that one of the courses links to a Moodle 1.9 instance course via MNet, which will be upgraded, but not until later in the year due to significant work required on modifying custom modules to suit Moodle 2.3.
Will a Moodle 2.3 instance connect correctly to a Moodle 1.9 instance via MNet, or should I postpone the upgrade until both sites can be upgraded at the same time ?
We have upgraded to 2.3 and have maintained mnet links to 1.9 sites. From memory, after upgrade we double-checked the peer keys and may have had to manually force a refresh. But otherwise has been operating as expected.