Which one of the following is a port and protocol combination allowed by the Allow Default setting for Port Lockdown?

The "Allow Default" setting for Port Lockdown on a BIG-IP system's self IP address permits a specific set of essential network protocols required for administrative access and high availability functions. This default list explicitly includes TCP port 443, which is used for secure HTTPS access to the BIG-IP Configuration utility (web GUI). This ensures that administrators can manage the device securely over the network without having to create custom rules for this fundamental service. The default configuration prioritizes secure management protocols.

A. TCP 80: This port for HTTP is not included in the "Allow Default" list. F5 promotes secure management access via HTTPS (TCP 443) by default.

B. UDP 8443: This port and protocol combination is not part of the standard "Allow Default" service list for any default BIG-IP management or high availability function.

1. F5 Networks Knowledge Base, K17333: Overview of port lockdown behavior.

Section: "Allow Default"

Content: This document explicitly lists the default protocols and ports permitted by the "Allow Default" setting. It states: "TCP port 443 (HTTPS)" is included for the Configuration utility. This article serves as the primary source for the default port list.

2. F5 BIG-IP System: Administration Guide.

Chapter: "Securing the BIG-IP System" -> Section: "Securing access to the BIG-IP system" -> Subsection: "Using port lockdown"

Content: The guide explains that the "Allow Default" setting is a pre-configured list of allowed services on the self IP address, which includes essential services like HTTPS for the management GUI, SSH, and iQuery. It confirms that TCP 443 is a fundamental part of this default set.