When using the factory-default configuration, which VLAN is assigned to all interfaces on an EX Series switch?

In a factory-default configuration on an EX Series switch, all interfaces are assigned to VLAN 1. VLAN 1 is a default VLAN that exists on most network switches and is often used for management purposes. This default configuration is typical for numerous switch manufacturers, including Juniper, and simplifies the initial setup for users, allowing for basic connectivity without the need for extensive configuration.

Though the question provides various choices, only the acknowledgment that VLAN 1 is the standard assignment helps clarify that this specific VLAN functions as the management VLAN by default unless explicitly changed. The other terms mentioned, such as Native, Default, and Unnumbered, do not specify VLAN 1 in this context and have distinct meanings within networking. For example, "Native" usually corresponds to the VLAN used for untagged traffic in trunking configurations, while "Default" and "Unnumbered" may refer to different concepts regarding IP addressing or unsupervised configurations. This highlights the importance of understanding the default assignment of VLANs within a switch's initial setup for ease of management and operational readiness.