Airplay issues with Airport express

[Daniel Sandstrom]

Hi,

We have issues with Airplay for Apple Airport express boxes. WLC is running 7.4.115 and clients are sitting on a 2602 flexconnect ( Multimedia SSID is switched centrally ). Mdns snooping enabled for Airplay and Airtunes.

We have three Apple TV's which works perfectly both picture/sound - problems seems to be the implementation of the Airport Express in combination with Bonjour GW in the WLC.

After som troubleshooting I can see that there is a difference how Apple TV and Airport Express announce their Bonjour services in regards to the airtunes service ( _raop._tcp ) . AppleTV announces only it's real IP adress for the _raop._tcp service but the  Airport express announces both its real ip adress and an ipv4 link local ( 169.254.x.x ) address. This is where the problem starts... After a reboot of an Airport Express I can see that the correct real IP address is snooped, but after a short time it falls over to the link local 169.254.x.x address,  clients ( iPads for example ) see the Airport express just fine but cannot send audio to it since it tries to send to the link-local IP instead of the real one.

It seems that this behaviour is built into the A-Expresses and probably has to do with the fact that it should be possible to find an A-express from the Airport setup utility program on the PC/MAC without the A-express having an IP adress first. I also would like to see possibility for the Bonjour/MDNS implementation in the WLC to filter out link-local addresses not to be snooped at all..

Anyone found a workaround for this behaviour ? Is it a bug ?

[Saravanan Lakshmanan]

it doesn't work and it is not supported by cisco. same is documented in cisco bonjour guides.

[Daniel Sandstrom]

I think this needs clarification in the bonjour guide if this is the case , I cannot find it mentioned anywhere that an Airplay ( sound only ) setup with an Airport Express shouldn't work ..  

[Saravanan Lakshmanan]

My bad, I was incorrect. there is an internal bug - mDNS records which have link local ip should be ignored by WLC -

the bug is fixed on 7.5.102.0 code.

TimeCapsuleBackup always advertise both real ip & link local ip in mdns records
Controller snoops the link local ip and the same send to client when it is queried
Due to this issue TimeMachine Backup is not working from client side

TimeCapsule cannot be discovered by wireless Apple client with WLC. All WLC configuration are correct.
The reason for it is because TimeCapsule advertises two ip address in the mDns query response:
1- its ipv4 real ip address
2- its link ip address 169.254.x.x

the WLC forwards the incorrect IP address to the client.

[Daniel Sandstrom]

Sounds like we hit this bug for sure ...  good to know that it has been fixed in 7.5.102.

[Saravanan Lakshmanan]

Please Mark it as answered to help out others. (I've also spent siginificant amount of time to unearth it.)

[Daniel Sandstrom]

Confirmed OK after upgrade - thanks !

[Michael Benadiba]

using the Apple AirPort Utility (either on iPhone or Mac/PC) I was Unable to discover my AirPort devices from an iPhone on the WLAN (connecting to AirPort on Wired) until I manually added in the custom airport mDNS Service.

on a Cisco WLC Wireless Lan Controller 2504 running 8.0.115 firmware, Navigate to the Web GUI:

Controller > mDNS > General

under "Select Service" choose Other. This allows you to create a custom mDNS Service

Service Name: AirPort

Service String: _airport._tcp.local.

Enable Query Status.

Disable LSS Status

Origin: ALL

Click ADD

This adds the necessary mDNS Service Name to the mDNS Service Provider Master Database which allows the Apple AirPort Utility on an iPhone or Mac/PC Laptop on the WLAN to discover AirPort devices on the Wired network (or vice versa).

You will then need to add this new custom Service to the default-mdns-profile.

Controller > mDNS > Profiles

Click on the default-mdns-profile

Under the Services List, choose the new AirPort Service in the Service Name Drop Down.

Click ADD.  This adds the new AirPort service to the default-mdns-profile so that Controller will add the AirPort Discovery service to the supported AirPort Devices.

This assumes you have a default config and are using the default-mdns-profile