Database system cannot be reached

What causes this issue?

The database system &V1& is not accessible.

System Response

The system tried but failed to establish a database link. A short dump
has been registered.

How to fix this error?

Check
the settings in the link-maintenance screens,
whether your application server is configured as a client of the
database that you want to connect,
whether the database system can be accessed over the network.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.