A programmer wants to configure a database to only allow read or write access when requests are coming from specific IP addresses. Which of the…

A firewall is a network security system designed to control network traffic based on a set of security rules. To restrict database access to specific IP addresses, a programmer or administrator would configure firewall rules. These rules would create an "allow list" (or whitelist) that permits traffic from the specified source IP addresses to the database server's listening port while denying all other traffic. This is a fundamental method for network-level access control and securing database servers.

A. Static IP address: A static IP address is a fixed address assigned to a client or server; it is not the mechanism used to configure or enforce access rules.

C. Dynamic IP address: A dynamic IP address changes over time, making it unsuitable for creating stable and reliable access control rules for authorized clients.

D. IDNS: This is not a standard acronym for a technology that controls database access. The Domain Name System (DNS) resolves names to IPs but does not enforce access policies.

1. Microsoft Corporation. (2023). Configure the Windows Firewall to Allow SQL Server Access. Microsoft Learn.

Reference: In the "Overview of Firewall Configuration" section

the document states

"To access an instance of the SQL Server through a firewall

you must configure the firewall on the computer that is running SQL Server... The firewall is a component of Microsoft Windows." This official documentation confirms that a firewall is the tool used to configure IP-based access to a database.

2. The PostgreSQL Global Development Group. (2024). PostgreSQL 16 Documentation

Chapter 21: Client Authentication.

Reference: Section 21.1

"The pghba.conf File

" details how PostgreSQL uses a configuration file that acts as a host-based firewall. It states

"Client authentication is controlled by a configuration file

which traditionally is named pghba.conf... A record can have one of the following formats... host ... address [CIDR-address]." This demonstrates a database-specific

built-in firewall-like mechanism for IP-based access control.

3. Massachusetts Institute of Technology (MIT) Information Systems & Technology (IS&T). (n.d.). Securing Oracle Databases.

Reference: In the "Network Security" section

the guide explicitly recommends: "Use a firewall to restrict network access to the database server. Only allow connections from hosts that need to connect to the database." This university resource validates the use of firewalls as a best practice for securing databases by restricting access to specific hosts (identified by IP addresses).