Go to portal.azure.com and sign in with the account that owns the Garnet subscription.
Use the top search bar and type garnet-sql. Pick the result whose type
is SQL server — a database has a similar-looking name but a different icon, so double-check the type column.
Under Security in the server's left-hand menu, click Networking (older portal versions call this "Firewalls and virtual networks").
Under Firewall rules, click + Add a firewall rule, then fill in:
Use the same value for Start IP and End IP unless the host is known to use a range of outbound IPs.
Click Save at the top of the Networking page. Changes take effect in about 1–5 minutes — no restart of the SQL server needed.
Reload cwaMESG (or hit / on it again). If the firewall rule was the
only problem, the 500.30 startup error goes away and the sign-in page loads normally.