Why does a Canon MF451dw All-in-One periodically disappear off home network?

Sitting here working away and the Canon MF451dw All-in-One has disappeared off the home network twice this afternoon, both times for a couple of hours. The D-Link router has an IP address properly reserved for the printer. That address is statically set on the printer, and Status Monitor on the printer reports that (not a global default IP address) as the IP address even when it's invisible. The printer is connecting wirelessly, and reports medium signal strength even when not appearing on the network. Ping to its IP address succeeds when the printer is visible on the network (meaning visible

Question by PGeerkens on Super User, licensed CC BY-SA. We show a short excerpt and link to the original thread as credit.