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We set up AirPrint using unicast DNS-SD on our campus about a year ago and it turned out to be a big success, so we're looking at trying to get AirPlay working so our faculty and students can wirelessly show content on our classroom projectors.

There are still a couple of other things preventing an ideal implementation (username and password authentication, for starters), but I've been trying to set up a working demo nonetheless. Getting AirPrint working was basically just a matter of advertising the same records over a DNS-SD domain instead of the multicast (.local) one, but doing the same thing for AirPlay doesn't seem to cut it. The devices don't recognize the DNS-SD AirPlay servers as available.

I've uploaded a screenshot of my DNS-SD configuration with the original (from AirServer, which works normally for multicast) here.

I realize this is still a fairly new feature and documentation is lacking, but has anyone been able to get AirPlay working via DNS-SD? If it simply only works over multicast, I can accept that, but its potential is so appealing for us that I thought it'd be worth asking if anyone else has figured it out.

petrus
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Moduspwnens
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2 Answers2

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I've gotten this to work, but the method wasn't pretty. Because the multicast address for airplay is subnet local -only- it can't be propagated as-is by a standard router. I ended up setting up Avahi on a Linux vm with interfaces into each required subnet. Avahi was, in turn, configured for service reflection (enable-reflector=yes). This allows the daemon to gather the various mDNS requests and propagates them into the various connected subnets.

I'm not especially a tremendous fan of this solution, but it does work for a dozen or so VLAN's without too much drama. The moral of this story is, unfortunately, that these protocols are, at best, problematic.

rnxrx
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  • That's the best workaround for the problem that I've found so far, but my question specifically pertains to DNS-SD, which is the unicast component. So far AirPlay is the only Bonjour service that I've found works over mDNS only, but not DNS-SD... which is what leads me to believe I might just be missing something. Without any documentation, though, asking if anyone else has figured it out is all I can really do. – Moduspwnens Oct 04 '12 at 22:18
  • I never could get airplay to work with DNS-SD, hence the mDNS repeater option. As you've apparently noticed, the documentation from Apple about how airplay actually works is pretty much nonexistent. From watching through Avahi's browser, sniffer, etc you may be able to work backward but my impression was that it was nontrivial. – rnxrx Oct 04 '12 at 23:14
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Apple apparently made sure Apple TVs don't work with unicast DNS-SD as "a concession they made to content providers and that no amount of DNS records or search domains would allow the Apple TV to be contacted/used from another network." So you're out of luck, unfortunately.

TRS-80
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