TOPIC:

Having resolved the problem and seeing several people stumbling across the same let me summarise the findings (courtesy of both miniDSP and Dirac Live support)

To start with, there may be two , independent issues, both related to firewall/ports availability:

1. mindsp cannot "invoke" the right IP ("app cannot resolve the hostname to the correct IP" might be technically more correct) . The solution here is to start minidsp from the terminal as I described above with an explicit --ip argument like ./Applications/miniDSP/SHD.app/Contents/Resources/add/minidsp_dirac --ip X.X.X.X. where X.X.X.X is the SHD IP address.

if everything goes well you should see in the terminal the two ports being engaged, like:
2020-11-12 08:13:57 INFO [main] Server started listening on port 5000...
2020-11-12 08:13:57 INFO [runChangedIpJob] Started http server on port 8080

In case the system cannot resolve the host correctly you may (like me) get stuck on "listening on port 5000"... whilst the http server on port 8080 is never started.

2. problems directly related to the DiracLive app: when starting the Dirac Live app standalone (even with the SHD disconnected) instead of going into the page displaying "no device found" the app displays (for several seconds) "testing connection to servers..." and after eg. 30' or more an error message "no servers could be found check... firewall .... settings" appears.

This was for me the more difficult problem to solve as (I) the miniDSP team could not provide any hints and (II) even temporarily disabling the firewall could not alleviate the problem (on my machine. On my daughter' Mac also running Catalina 10.15 everything was fine!) .

I eventually managed to overcome it by carefully updating all software and apps on my Mac although I could not trace which of these operations did the trick. Dirac support insists that it is indeed a firewall issue with two ports (11113 and 11115) required to communicate with their authentication server; apparently there is a plan to transfer this functionality to a standard port in the future to avoid similar issues.

Hope the above is of some use to SHD users,

Greg

Thanks to michelangelo it is working for me now (MacOS Catalina). See here:

www.minidsp.com/forum/shd-series/17515-s...found?start=15#51914

Nocko!