Hi all,

I am hoping someone can help me out with a problem I'm having with a set of Denon HEOS speakers. From what I can determine these use Bonjour/ZeroConf/mDNS/Multicast for configuration and access. I have two of these (KitchenRight and KitchenLeft which are then "paired" as Kitchen). The symptoms of the problem are that the HEOS app very intermittently "sees" the speakers, and apps such as Spotify will work on some devices but not others (all on the same SSID/VLAN). Further, I think, there's a bit of a timing issue where the speakers "appear" for a few minutes when powered on then "stop responding" a few minutes later.

Here's details of my configuration:


Vigor 2832 (RTR1)
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TRUNK MEMBER VLAN 1, TAGS 2 ,3
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Netgear Layer 2/3 switch (SW1)

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VLAN MEMBER 1, TAGS 2, 3
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TRUNK VLAN MEMBER 1, TAGS 2 ,3

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AP902 (AP1)
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Netgear Layer 2/3 switch (SW2)

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|VLAN MEMBER 1, TAGS 2, 3

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AP902 (AP2)


The speakers are connected to AP2 (AP1 is too far away for them to see), the clients for the speakers are also connected to AP2.
AP1 and 2 are broadcasting 3 SSIDs:
WIFI-Work (VLAN 1)
WIFI-Home (VLAN 3)
WIFI-Guest (VLAN 4).

AP1 is running 2.4ghz and 5ghz with band steering (AP1 is not used in this scenario)
AP2 is running 2.4gh only (turned off 5ghz in case this was something to do with a bug in multicast traversing the bands)
Both APs have isolation turned OFF
The trunk ports on the netgear L2/3 switches are members of VLAN 0 and tagging VLANs 1,3,4
VLANs:
1 (management/default) 192.168.1.1 (routed into 3)
2 (spare/resource) 192.168.1.2 (not routed)
3 (home) 192.168.1.3 (routed into 1)
4 (guest) 192.168.1.4

The switch config is "vanilla" other than the VLAN tagging on the trunk and AP ports.

I think I've just hit and solved a similar one, though I'm using a 2860, AP910's, and a Netgear GS748 with Daikin aircon controllers. Regularly Android phones failed to find the a/c units.

Firstly the 2.4/5GHz isolation needs to be off (only found that setting today).

The second is IGMP management within the switch. Bonjour is using multicast address 224.0.0.251 / 01:00:5E:00:00:FB. If the switch is doing IGMP snooping then it needs to get IGMP membership requests at regularly intervals. It seems that various implementations of Bonjour are failing to send these, therefore the switch is unsubscribing ports (including the ones going to the other AP) from the multicast group.
On the GS748 I can add a static multicast group membership to always forward certain multicast addresses to some/all ports, and doing that seems to have certainly helped, although I can't say yet if it has fully solved the problem.