Firewall requirements

The following ports and addresses should be open in the firewall.

# backend communication
HTTPS  (443/TCP)  nedap-harmony.com

# error logging
HTTPS  (443/TCP)  http-intake.logs.datadoghq.eu
HTTPS  (443/TCP)  o402436.ingest.sentry.io

# time-synchronisation
NTP    (123/UDP)  0.pool.ntp.org