Site Local Scope on Wifi

[benjaminriggenbach]

Hello.

We use some devices wich are able to transmit uncompressed audio. The protocol is Dante by Audinate.

The protocol can send data via unicast and multicast, if more devices are feed with the same stream.

The multicast mode uses the Site Local Scope 239.255/16 Addresses.

I do not want to transmit the stream over wifi, but i would like to know, why this stream does not get transmitted over the wifi? 

I couldn't find a hint in the rfc2365 standard, that this scope is blocked anyway on wifi connections.

The AP i used for that is a Air-SAP702I-E-K9. I configured it myself and i did not explicit allow multicast nor deny it.

Some of the control data and device detection process is transmitted via mdns and this works fine. So i figured it can't

be a general multicast issue.

Is there a general rule about this site local scope that it can't be transmitted over wifi anyway or something?

Thanks for the help.

Regards,

Benjamin

[patoberli]

Cisco has igmp snooping enabled by default (as far as I remember) on its switches since many years. By disabling it you might be flooding a port with "useless" traffic, or even overload the switch cpu.



The 1242 hasn't igmp snooping disabled in its configuration, in other words it's probably enabled :)

[benjaminriggenbach]

Yes that's true, the 1242 has it enabled. The setup works fine when hooked up like in my plot but just the AP is swapped to the 1242 and if snooping is enabled or not has no affect, it still works fine.

All these things always lead me back to the thought, that the different ios versions handle the flooding differently. Even when snooping enabled on an AP, the LAN interface of the AP can't prevent the traffic from entering it. It's just a matter of what does the ios do with it then, right? Or can it be something in hardware? 

[patoberli]

Could be both, don't know.

[benjaminriggenbach]

Well... bummer..

But thank you very much for all your time. It helped me to get a little further with my understandings.

[patoberli]

You still haven't me provided with the show version :) So I still can't check if you're maybe hitting a bug.

But yeah, wireless and multicast works in "mysterious" ways sometimes. Some products supporting some features, others none.

[benjaminriggenbach]

Oh i thought i did add the versions.

I've attached them now, sorry.

[patoberli]

Wow, this software is ~6 years old, there have been around 20-30 updates since.
I suggest you test with the latest release ap1g1-k9w7-tar.153-3.JI3.tar. They did fix various issues, including some performance bugs.
I don't know if it will indeed help with the problem here, but it will fix various other bugs you might have encountered in the past.
It also adds some required ETSI upgrades, to make it conform with the latest EU regulations. If that isn't reason enough to upgrade, I don't know (some sarcasm here) :)

[benjaminriggenbach]

Hey patoberli.

I'm currently on vacations that's why it is a bit on hold.

The other issue is, that it seems to be a hard task to get the target software.

I'm on it and i hope i can report something with a newer software version.

Thanks to this point.

[patoberli]

Yeah, you do need to have at least 1 AP of this series covered under a service contract to be able to download software. I suggest you contact a Cisco reseller and ask them for a contract.

[benjaminriggenbach]

Hello patoberli.

I managed to upgrade to the latest IOS.

I run it with the same startup-config and the situation hasn't changed, unfortunately.

[patoberli]

Ah to bad. Then I'm more or less out of ideas at the moment, other than saying "multicast over wireless should be avoided at all costs".