mDNS bug: imageCLASS MF663Cdw not discoverable via Air Print when in sleep mode

[Fribur]

Air Print works just fine when printer is on, but printer is not discoverable when in sleep mode. Googling this issue leads me to conclude this is a know issue of all Canon printer since a number of years, and is likely caused by some issue with advertisement of the print service via mDNS. To debug this issue, I used the App Discovery DNS-SD Browser (see screenshots)

Turns out that also this app can sometimes see the service, and quite often not, and never when the printer is in sleep mode. So looks like this is most likely an issue with the implementation of the mDNS service by Canon. As there are many reports about this issue since numerous years in this forum and elsewhere, I wonder if a Canon engineer ever looked into this issue? Screenshot of when mDNS discovery works (visible via AirPrint) and when not attached. What works to mitigate the issue for while is to turn off "Private WIFI Address" on the iPhone...but this really only works for 5 minutes or so until the printer is invisible again to Air Print.

It would be great if Canon could resolve this mDNS issue for good, as the printer is advertised with the "Apple Air Print" feature, and I would not consider it an acceptable implementation when it is required to always go to the printer to turn it on for this feature to work. My 12 year old Brother printer had no such issue, Air Print always worked just fine regardless if the printer is in sleep mode or not.

[Fribur]

Update: When I smash the "refresh" button for about 1 minute (in the discovery app or in the Air Print printer selection menu), the printer eventually shows up. So looks like some timing issue responding to the mDNS multicast query. I also noticed the printer Remote UI  web interface sometimes has a 10 second or so delay when the printer is in sleep mode. Same root cause? 

[shadowsports]

Greetings,

Try assigning a static IP to the printer on your router.  This will likely keep records active and allow queries to resolve correctly, even if the device is in sleep or the adapter is in a low power or standby state. "🌙 Icon" illuminated.

This could also be impacted by the brand and  model of your wireless router.  Ensure it's running the latest firmware available.  

I'm aware that people have been leaving comments regarding mDNS for a long time.  My MF644Cdw sits behind an Asus mesh system and is used almost exclusively with apple devices.  It sleeps after a minute of inactivity.  It never fails to wake when a print job is sent to it.  

I have not checked to see if it's using bonjour or unicast on Port 5353 but it always prints.  mDNS is active.  

[Fribur]

Hi Rick, Many Thanks for your reply and effort to help: truly appreciated! I tried static IP and many other things on the printer (e.g. disable WIFI low power mode) and in router…no change. At this point I am pretty sure this is not a setting issue but a genuine bug. BTW I think bonjour (which handles the printing/data transfer) is working, it is just not visible to Apple devices (mDNS multicast) unless I keep trying for a minute. Do know how to get this bug into Canon backlog? Do you got any connection to a Canon engineer? I could try calling them and risk getting stuck in the hotline for hours…

Cheers

[Fribur]

Here btw link to another user having same issue with ImageCLASS MF453dw https://community.usa.canon.com/t5/Printer-Software-Networking/ImageCLASS-MF453dw-Bonjour-mDNS-not-w...

[shadowsports]

I would reach out to support directly.  Start by registering your product in your MyCanon account.  Then contact support 1-800-652-2666

I'm only using AirPrint on mobile devices. iPhone 11. iPhone 15 and some iPads.  I install drivers on my MAC laptops and install the printers as IP devices.  Guests can print from their Apple devices when they visit as well.

When I call support the longest I've ever had to wait is about 5 minutes.  Typically I'm speaking to somebody in about 2 minutes or less.