Skip to content

module-zeroconf-discover gets highly confused when two network interfaces are in the same network segment

Submitted by Rudd-O

Assigned to pul..@..op.org

Link to original bug (#45858)

Description

When two network interfaces are in the same network segment, and a remote server is available, avahi reports this:

~@karen.dragonfear α: avahi-browse -a | grep pulse

And the sink appears in the local server as a remote sink.

When one network interface is disconnected, this happens in avahi:

The sink DISAPPEARS from pulseaudio volume control. However both sink and server CONTINUE to be available in wlan0:

Note that, at this point, connecting p5p1 again makes the sink reappear in pulseaudio volume control.

This points to a bug in module-zeroconf-discover, where it does the simpleton thing of adding a sink by name when it sees the sink appear, and removes it when it sees the sink disappear.

What it should do instead, is keep a reference count to the sink, and increment the count when it appears on a network interface in avahi, decrement the count when it disappears on a network interface, and only display it as an available sink when the reference count is >0. Alternatively, PA zeroconf-discover could consult avahi to see if a sink with the same name continues to be available in another network interface.

Thanks in advance for the fix! :-)

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information