OpenVPN, Tunnelblick, bridged network (tap device), mDNSResponder, and daapd on OS X

tried to get the music library from a server running firefly to a mac via an OpenVPN tunnel 

- where the same server is also the OpenVPN server and is using a tap device and

- the mac was using Tunnelblick 

though this setup seemed to work for my linux machine it didn't quite do the job on the mac: there the mdns information was only used occasionally (though ethereal aka. wireshark confirmed that it was being transmitted).

currently i think that the mDNSResponder is behaving - at least - strange and a possible work-around seems to be 

- install the tun/tap-driver separately from Tunnelblick (so the driver is loaded at boot time and mDNSResponder is not 'surprised' by its late appearance...)

- turn the interface of the internet connection (the one tunnelblick uses to connect to the server - not the tap one...) off and on