Which Port Is Used for SQL Database Command-Line Connectivity?

N10-008 By islever Editorial Last updated

Short answer

D 1521

Question

A technician is troubleshooting a SQL database connection. After remotely connecting to the end client, the technician tests basic connectivity. Which of the following ports is available to connect via command-line interface?
  1. 143
  2. 445
  3. 993
  4. 1521 Correct Answer

Key Takeaways

This question tests your ability to identify default database service ports among common network ports, with a trap of confusing SQL-related services with email or file-sharing ports.

Port 1521 is the default port used by Oracle SQL databases for SQL*Net connections, making it the correct choice for SQL database command-line connectivity. Community consensus strongly supports answer D, with 82 votes versus 18 for port 445.

Common mistake: The most common wrong answer is B (445), which is used for SMB/CIFS file sharing and directory services, not for SQL databases. Some test-takers may mistakenly associate 445 with Microsoft SQL Server, but SQL Server uses 1433 by default.

Expert Analysis

Why the Answer Is Correct

Port 1521 is the well-known default port for Oracle Database's SQLNet listener, which handles client connections to Oracle SQL databases. Comment [1] correctly states that port 1521 is commonly used by Oracle SQL databases for SQLNet connections, while comment [3] explains that this port allows database servers to service client requests transparently.

Why the Other Options Are Wrong

Port 143 is used by IMAP (Internet Message Access Protocol) for email retrieval, not for database connectivity. Port 445 is used for SMB/CIFS file sharing and Microsoft directory services, not for SQL. Port 993 is used for IMAPS (secure IMAP) for email, not for SQL database connections. Comment [1] accurately explains each of these incorrect port usages.

Community Comment Notes

Most commenters support D (1521), as seen in votes (D: 82, B: 18) and comments [1], [2], and [3]. Comment [2] notes that given the context of SQL and database management, port 1521 is most appropriate. One comment [4] simply states "It's 445," but this is incorrect because 445 is SMB, not a SQL listener port. The consensus is clearly D.

Official Reference

These links open the official vendor documentation in a new tab.

Exam Strategy

Memorize the default port numbers for major database services: Oracle uses 1521, MySQL uses 3306, and Microsoft SQL Server uses 1433. On port identification questions, immediately eliminate ports that are clearly for email (143, 993, 110, 995) or file sharing (445, 139, 137/138) unless the question explicitly mentions those services.

Community Votes

D
82%
B
18%

82% of anonymous learners picked answer D. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 5 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 5

  1. a87d6a4 👍 4 Answered D
    Port 1521 is commonly used by Oracle SQL databases for SQL*Net connections, making it the correct port for connecting to an Oracle SQL database. A. 143: This port is used by the Internet Message Access Protocol (IMAP) for email, not for SQL databases. B. 445: This port is used for Microsoft Directory Services and file sharing (SMB/CIFS), not for SQL databases. C. 993: This port is used for secure IMAP over SSL/TLS, not for SQL databases.
  2. Mamad66 👍 2 Answered D
    The correct answer is D. 1521. Port 1521 is typically used for SQL*Net, the network interface used by Oracle Database for networked client access. It allows the database server to service requests from the client in a manner that is completely transparent to the client.
  3. TrebleSmith 👍 2 Answered D
    Port 1521 is used by Oracle Database. Given the info we are given, port 1521 would most likely be the most appropriate for this situation, seeing as SQL deals with managing databases. Let me know if I am incorrect on my assumption.
  4. schoha8874 👍 2 Answered B
    It’s 445
  5. Zach123654 👍 1 Answered D
    gpttttt

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