mDNS / Airprint not working on 3504 WLC

[Paul.Ostaszewski]

I was previously running a Cisco 5508 WLC running 8.5.182.0 and had mDNS working with no issues.  I recently removed the 5508 from my network and installed a HA pair of 3504's running 8.10.196.0 in its place.  I have one SSID that all my wireless devices connects to.  These devices include 1 HP M452DW color laserjet printer, two iPhone 16 pro's running iOS 18.1.1, 1 iPhone 6s running iOS 15.8.3, 1 iPad 6th gen running iOS 17.7.2, 1 iPad 10th gen running iOS 18.2 and a couple of windows 10 pc's.  

Having the 5508 side by side with my 3504, I went page by page in the GUI and configured everything from the interfaces, WLAN's, including the mDNS settings.  

I cannot for the life of me get Airprint to work from my apple devices to the HP M452DW printer using the 3504 WLC's.  All apple devices and the printer, are on the same SSID/network.

Can someone please walk me through what to check in order to get this working again?  My 6 year old can't print from her iPad anymore and its really bumming her out.

Thanks in advance!

-Paul

[Rich R]

Have you checked through the config guide:
https://www.cisco.com/c/en/us/td/docs/wireless/controller/8-10/config-guide/b_cg810/multicast_broadcast_setup.html#concept_D4C479155D1A4024804CA7230E939D87
and troubleshooting guide (although it's quite old so might not be up to date for 8.10):
https://www.cisco.com/c/en/us/support/docs/wireless/wireless-lan-controller-software/210835-Troubleshooting-mDNS.html

[Paul.Ostaszewski]

Went through this just now and set everything as is stated.  Still no airprint.

[ammahend]

in your case everything is connected to same SSID meaning same vlan or broadcast domain, so there is no role of 3504 controller as mDNS gateway, it just need to bridge mDNS traffic without touching or catching anything.

so check following things

1. disable mDNS snooping, its enabled by default, under Controller>mDNS>General

2. under your SSID>Advanced>P2P Blocking action should be disabled.

3. Controller>Multicast>Check enable global multicast mode

4. Controller> set Ap Multicast mode to Multicast (that's the only mode supported on 3504), give an IP may be 239.0.0.1

5. make sure printer and phone are connected to same SSID by looking into client monitoring page on WLC.

[Paul.Ostaszewski]

Tried what you wrote here and still no AirPrint.

[ammahend]

try the debug suggested below, also what about other services can use use AirPlay on Apple TV, can you use Roku or some other device than Printer ? I am sure you have tried restarting devices if not restart iphone, printer, AP and WLC if possible, don't restart all, start with printer and check if it works, then Phone, then AP, then WLC.

[Paul.Ostaszewski]

Hello.  Sorry for the delay.  I have tried restarting all devices, one at a time and that has not fixed the issue.  I have multiple roku devices on my network.  I am able to use the roku app on my iphone to control the roku devices still.  My test was opening the roku app and then connecting to one of the roku devices and using the remote on the app to control the roku device.

I have run "debug mdns all enable" but i am not getting much output on the console.  Where are the logs stored or are they being sent to the console only?

[ammahend]

seems like WLC is bridging mDNS traffic.

The issue seems local to the printer.

Next step will to make sure the printer is even advertising these services, you can SPAN the port where printer is connected to another port, connect a wireshark to that port, do a capture and share output, so that we can see what services printer is advertising, if you want to keep the capture small add filter of udp.port==5353

[Paul.Ostaszewski]

Unfortunately, the printer is connected via WiFi only on the same WLAN as the iPhone/iPads.  The printer is advertising because Airprint worked on my previous controller.  Going from the 5508 to the HA pair of 3504's is all that's changed on my network.

I've rebooted the printer... I've even tried to disable Airprint and re-enable it.  Neither have helped.

Is there any other way to detect if the printer is advertising?

[Flavio Miranda]

@Paul.Ostaszewski 

 Enable debug on the WLC with "

debug mdns all enable

Run tests and share the logs. Let´s see if we get something.  

[Paul.Ostaszewski]

I have run "debug mdns all enable" but i am not getting much output on the console.  Where are the logs stored or are they being sent to the console only?

[Flavio Miranda]

WLC does not hold much logs. 

You can save the log session

[Paul.Ostaszewski]

If you are speaking about what is being displayed to the console, there isn't much.  

[Flavio Miranda]

That´s weid. Are you sure you have it enabled?

https://www.cisco.com/c/en/us/td/docs/wireless/controller/8-5/config-guide/b_cg85/multicast_broadcast_setup.html#task_03422F526369449EBDE486B7030589B7

[Gaurav Kansal]

Hi,

Please confirm your WLAN setting, is there any option selected in P2P blocking action.? If it is disabled then it suits your requirements, but if it is set to 'Drop' or 'Forward-upstream' I would suggest you to plan it to change to disable it. Also confirm your topology like are you using flex connect.?
Regards
Gaurav Kansal

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