SK0-004 · Question #894
During monthly security scans, a new server is found on the network. It is determined the server is question is listening on the following TCP ports: 25, 80, 110, 443, and 587. Which of the…
The correct answer is C. Mail server. The open ports 25, 110, and 587 are standard mail protocol ports, identifying this server as a mail server with web access support on 80/443.
Question
During monthly security scans, a new server is found on the network. It is determined the server is question is listening on the following TCP ports: 25, 80, 110, 443, and 587. Which of the following roles is this server MOST likely fulfilling?
Options
- AWeb server
- BDatabase server
- CMail server
- DDirectory server
How the community answered
(26 responses)- B4% (1)
- C92% (24)
- D4% (1)
Why each option
The open ports 25, 110, and 587 are standard mail protocol ports, identifying this server as a mail server with web access support on 80/443.
A dedicated web server would only listen on ports 80 and 443 and would have no reason to open mail-specific ports such as 25, 110, or 587.
Database servers listen on engine-specific ports such as 1433 for MSSQL or 3306 for MySQL, not on mail transport or retrieval ports.
Port 25 is SMTP used for server-to-server mail transfer, port 110 is POP3 used for client mail retrieval, and port 587 is the SMTP submission port used by mail clients to send authenticated outbound mail. Ports 80 and 443 support a webmail interface, and together this combination is characteristic of a mail server role.
Directory servers use LDAP on port 389 and LDAPS on port 636 for directory queries and would not listen on mail protocol ports.
Concept tested: Mail server port identification - SMTP POP3 submission
Source: https://learn.microsoft.com/en-us/exchange/mail-flow-best-practices/mail-flow-best-practices
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