Bonjour Discovery browser and cisco WLC mDNS

[andrewswanson]

Hello
I'm using a Bonjour Discovery browser on an iPad to see if I can check what Bonjour services are available on a cisco 2504 running code 7.5.102.0. WLC is configured as per cisco documentation for mdns:

• Multicast disabled on WLC
  
• wired vlan (with bonjour services) is trunked to WLC
  
• mdns profile configured and bonjour services are visible on WLC
  
• mdns profile applied to WLAN
  

when i connect an ipad to the wlan and start the browser, no services appear (2 are visible on the WLC). Debug on the WLC shows the following (where XX:XX:XX:XX:XX:XX is the iPad mac)

*Bonjour_Msg_Task: Nov 04 10:51:06.674: XX:XX:XX:XX:XX:XX Failed to updated data to Service Provider DB
*Bonjour_Msg_Task: Nov 04 10:51:12.798: processBonjourPacket : 935 Queried service-string : _dns-sd._udp.local. is not configured in MSAL-DB

Is it possible to get Bonjour Discovery browser working with cisco WLC?

thanks
andy

[Stephen Rodriguez · Accepted solution]

you need to enable multicast and broadcast forwarding on the WLC.

http://www.cisco.com/en/US/products/hw/wireless/ps4570/products_tech_note09186a0080bb1d7c.shtml

HTH,
Steve

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[andrewswanson]

thanks Stephen. I tried that previously (minus enabling broadcast forwarding). Will try this again and post back.

cheers

Andy

[andrewswanson]

Thanks again Stephen - this works fine. Ami I right in saying that:

1. when using multicast on the WLC for bonjour, client and bonjour service device must be on same vlan and the client running Bonjour Discovery browser will work as expected
   
2. when using mDNS gateway on the WLC for bonjour, client and bonjour service device can be on different vlans. WLC caches Bonjour advertisments and will respond to clients requesting these particular services - a client running Bonjour discovery browser will not work as expected because it is not requesting a WLC cached advertisment
   

Cheers

Andy

[Stephen Rodriguez]

that sounds about right, yeah

HTH,
Steve

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[kkelly]

But doesn't the Bonjour browser client issue a discovery request (on startup) then WLC should advertise its learned servies???

[andrewswanson]

Hello. Packet capture of the bonjour discovery browser (installed on windows) shows an MDNS standard query for the services _services._dns-sd._udp.local and _sleep-proxy._udp.local.. With Multicast enabled on the WLC, the Bonjour browser displays all available Bonjour services. With the mDNS gateway setup on the WLC, the Bonjour Browser displays no services (not even the ones cached on the WLC) but if I start an app that uses a specific service string that is cached on the WLC, the app works as expected.

hth

andy

[kkelly]

I saw the same type of behavour.  I took a stab with the whitepaper and two Apple TV's , one wired the other wireless.

From a wired client to wireless ATV I got one second of screen then the ATV displayed a very cryptic error message.

My bonjour browsers also showed no service advertisemnets.

Is it possible that the service you connected to was already cached on tyhe client (though I expect your Bonjour browser would have reported that) becasue with the apple devices there is  no way to staticly enter the service strings ... if only ...

I have to lab this up again and get TAC in on it.

[andrewswanson]

Hello. We tested the WLC mDNS setup with an ipad and a ProTools control app. I added the service string for the app to the WLC and it discovered a wired mac advertising that particular service. I connected an ipad to wireless and started the app and it immdiately listed the wired mac as a device running the required service. Unfortunately I don't have any packet captures for that process.

Cheers

Andy

[ajc]

Hi Andrew, I tried to implement Bonjour mDNS using version 7.5 but it does not work when I am connected on different subnets using Dynamic Interfaces for the Apple TV Device and Clients respectively. I have tried everything (Broadcast forwarding, global multicast enabled, AP multicast mode unicast or multicast, interface mdns profile = default, etc etc.

I have an Apple TV device in one dynamic interface and the ipad in another one. When I put both in the same VLAN it works immediately. I do not know what I am missing.

I need to check why. I changed the dynamic interface I created for the Apple TV device and created a new one pointing to the Management Interface of the WLC and it worked right away. This is what I have configured in the WLC at this point:

Controller --- > Multicast ---- > Enable Global Multicast = DISABLED, Enable MLD Snooping = DISABLED, Enable IGMP Snooping = DISABLED.

Controller --- >  General  ---- > Broadcast forwarding = DISABLED, AP Multicast Mode = UNICAST

Controller --- > Interfaces --- > Management = Being used by the WLAN/SSID = Apple TV Client

Controller --- > Interfaces ---- > APPLE Services = Being used by the WLAN/SSID = Apple TV

Controller --> Interfaces (EDIT) ---> mDNS = NONE for APPLE TV CLIENT

Controller --> Interfaces (EDIT) ---> mDNS = default mdns for apple tv device

WLAN --- > Advance --- > mDNS Snooping = default for both WLAN/SSID indicated above.

[Scott Fella]

Abraham,

Do you have multicast enabled on your wired infrastructure and PIM enabled on your layer 3 interfaces?  Just enabling multicast and mDNS on the WLC will not make bonjour work crossing layer 3.

Thanks,

Scott

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[ajc]

Thanks Scott for your note, I

[Scott Fella]

Your looking at v7.5 guide but your still using v7.3.  There are changes to mDNS on v7.5 and v7.6 which might be why your not seeing what you want to see.  I'm also assuming that the AP's are in local mode and not FlexConnect?

Thanks,

Scott

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[ajc]

Hi Scott,

I am using 7.5 on the controller, I was just mentioning what I had in the past and now I want to change it based on the new features included on this WLC version.

I checked something else based on your note and I found that I have configured pim sparse-mode in the VLAN corresponding to the WLC Management Interface but nothing on the VLAN for the Apple TV. I do not have multicast, broadcast forwarding, mld and igmp globally enabled in the WLC however it worked. My scenario = apple tv and ipad devices on the remote location connected to different subnets/ssid's and the WLC in the centralized DC. All the Apple devices connected to the wireless nothing on the wired side of the network until now (that is another test that I will run later)

I will try something else activating multicast on the dynamic interfaces based on the guide instructions and let you know.

Yes, local mode.

thanks again for your time and orientation.

[Scott Fella]

I have always used multicast on the wired side. Even in my home lab with multiple apple TV's and running Air Server. When I have disabled multicast, things break. I do things that have worked well for me:)

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