Firewall ACL Rules for Securing Email Server Connections

Secure Access Rules for Email Server

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Question

A network technician is configuring a firewall access list to secure incoming connections to an email server.

The internal address of this email server is 192.168.1.143

The firewall should allow external email servers to send email to the email server.

The email server also supports client access via a web browser.

Only secure protocols should be used, and only the necessary ports should be open.

Which of the following ACL rules should be configured in the firewall's WAN port? (Choose two.)

A.

Permit 192.168.1.143.25 B.

Permit 192.168.1.143.80 C.

Permit 192.168.1.143.110 D.

Permit 192.168.1.143.143 E.

Permit 192.168.1.143.443 F.

Permit 192.168.1.143.587

EF.

Explanations

A network technician is configuring a firewall access list to secure incoming connections to an email server.

The internal address of this email server is 192.168.1.143

The firewall should allow external email servers to send email to the email server.

The email server also supports client access via a web browser.

Only secure protocols should be used, and only the necessary ports should be open.

Which of the following ACL rules should be configured in the firewall's WAN port? (Choose two.)

A.

Permit 192.168.1.143.25

B.

Permit 192.168.1.143.80

C.

Permit 192.168.1.143.110

D.

Permit 192.168.1.143.143

E.

Permit 192.168.1.143.443

F.

Permit 192.168.1.143.587

EF.

The task of the network technician is to configure a firewall access list to secure incoming connections to an email server. The internal address of this email server is 192.168.1.143. The firewall should allow external email servers to send email to the email server, and the email server also supports client access via a web browser. Only secure protocols should be used, and only the necessary ports should be open.

The ACL (Access Control List) is used to specify which types of traffic are allowed and which types are blocked. ACL rules can be used to permit or deny traffic based on the source IP address, destination IP address, protocol, and port numbers.

The following options are provided:

A. Permit 192.168.1.143.25 B. Permit 192.168.1.143.80 C. Permit 192.168.1.143.110 D. Permit 192.168.1.143.143 E. Permit 192.168.1.143.443 F. Permit 192.168.1.143.587

To choose the appropriate ACL rules, we need to consider the following requirements:

  1. The firewall should allow external email servers to send email to the email server.
  2. The email server supports client access via a web browser.
  3. Only secure protocols should be used.
  4. Only the necessary ports should be open.

Option A: Permit 192.168.1.143.25 Port 25 is used for SMTP (Simple Mail Transfer Protocol), which is used to send email messages between servers. This rule would allow external email servers to send email to the email server. However, it does not satisfy the requirement that only secure protocols should be used. SMTP is not a secure protocol and can be easily intercepted.

Option B: Permit 192.168.1.143.80 Port 80 is used for HTTP (Hypertext Transfer Protocol), which is used to access websites using a web browser. This rule would allow clients to access the email server via a web browser. However, it does not satisfy the requirement that only secure protocols should be used. HTTP is not a secure protocol and can be easily intercepted.

Option C: Permit 192.168.1.143.110 Port 110 is used for POP3 (Post Office Protocol version 3), which is used to retrieve email from a server. This rule would not allow external email servers to send email to the email server. It only allows clients to retrieve email from the server using a non-secure protocol. This option does not satisfy the requirement that the firewall should allow external email servers to send email to the email server.

Option D: Permit 192.168.1.143.143 Port 143 is used for IMAP (Internet Message Access Protocol), which is used to retrieve email from a server. This rule would not allow external email servers to send email to the email server. It only allows clients to retrieve email from the server using a non-secure protocol. This option does not satisfy the requirement that the firewall should allow external email servers to send email to the email server.

Option E: Permit 192.168.1.143.443 Port 443 is used for HTTPS (Hypertext Transfer Protocol Secure), which is used to access websites using a web browser securely. This rule would allow clients to access the email server via a web browser securely. It satisfies the requirement that only secure protocols should be used. This option allows traffic from external email servers.

Option F: Permit 192.168.1.143.587 Port 587 is used for SMTP over TLS (Transport Layer Security), which is used to send email securely between servers. This rule would allow external email