Apple’s Worldwide Developers Conference to kick off June 10 at 10 a.m. PDT with Keynote address

The Keynote will be available to stream on apple.com, the Apple Developer app, the Apple TV app, and the Apple YouTube channel. On-demand playback will be available after the conclusion of the stream.

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Trunk14 Author

Level 1

11 points

Home Sharing over Ethernet

Ok, I am officially about to go insane.

Have used home sharing between my iMac and ATV 3 for years over WiFi with no major issues. Due to a recent move, the WiFi signal between the two is now pretty weak so switched everything to ethernet and now cannot get it to work for the life of me and I have no idea why.

Both iMac and ATV3 are connected to the same router, IPs, subnet mask, all that, are on the same network. I've changed the sharing name on my iMac as suggested elsewhere, I've turned everything off and on and again a thousand times. ATV3 has been reset and is only using ethernet, yet still it cannot find my library.

I am beyond baffled. Any help would be greatly appreciated.

Apple TV

Posted on May 1, 2015 12:45 AM

22 replies

Trunk14 Author

Level 1

11 points

May 14, 2015 9:00 AM in response to jjkraw

No problem, appreciate the help.

What I mean is that if I go to the orange 'Computers' icon on the ATV home screen I am constantly greeted with the message to turn on home sharing to access my library. Clicking on it does nothing. Home sharing is on on the ATV and iMac, both with correct account. The ethernet connection to the ATV is working (I can use Netflix etc) on the same home network as the iMac. I've checked this both ends.

If I unplug the ethernet from the ATV and turn WiFi on from the iMac, the message disappears and my library appears on the ATV as expected and I can select it, go in to Movies, TV Shows etc. The problem for me here is the WiFi signal is very unreliable in this office so streaming anything in HD becomes a buffering nightmare.

jjkraw

Level 2

449 points

May 14, 2015 9:09 AM in response to Trunk14

OK - so that most likely means that the mDNS isn't getting through properly via the Belkin. A quick Internet search showed a few instances of people complaining about other Belkin gear not working well w/ Bonjour, but not the powerline.

Another experiment you can run is to connect your MacBook to the Ethernet line that the ATV is using. If you don't see the library accessible in iTunes on the Mac, then the evidence really points to the Belkin gear.

Is there any type of management / web interface for the powerline equipment?

Trunk14 Author

Level 1

11 points

May 14, 2015 9:18 AM in response to jjkraw

Ethernet straight into the MacBook works fine, yes, it's definitely something that the Belkin is doing that's the problem (best guess anyway).

You can't login in to the powerlines anyway that I am aware of, no. Not overly familiar with the way that Bonour handles stuff TBH so haven't been able to troubleshoot from this angle.

If I login in to the router from the iMac however, I can see the ATV in the connected ethernet peripherals so it is at least seeing it in some sense, it's just not connecting properly.

jjkraw

Level 2

449 points

May 14, 2015 10:09 AM in response to Trunk14

All of Apple's "zero configuration" stuff runs over the multicast DNS, or mDNS protocol. These packets are identified as follows:

Destination MAC address (IPv4): 01:00:5e:00:00:fb

Destination MAC address (IPv6): 33:33:00:00:00:fb

Destination IPv4 address: 224.0.0.251

Destination IPv6 address: ff02::fb

But what it all comes down to is one bit: In the first byte (pair of digits) in either of those MAC addresses, notice that the least significant bit is set to 1. That is an indication to the networking gear that this is a multicast packet and should be flooded to the entire network (other than where it came in). It can get a little more complicated than that, but in general home networks are pretty simple. In most cases, everything received on one wire of a home router will be sent out every other wire (except the WAN port) and also via the wireless network(s).

It appears that the Belkin isn't doing that. I don't know anything about their support network, but you might try contacting them and let them know that multicast forwarding (in particular, multicast DNS) isn't working right.

If I login in to the router from the iMac however, I can see the ATV in the connected ethernet peripherals so it is at least seeing it in some sense, it's just not connecting properly.

That means that DHCP and unicast packets are getting through. DHCP uses a broadcast (ff:ff:ff:ff:ff:ff) MAC address, so it appears those are being forwarded correctly. None of that depends on multicast.