What VLAN ID value is associated by default with the default VLAN on EX Series switches?

The default VLAN on EX Series switches is associated with the VLAN ID value of 1. This is a standard configuration found in most VLAN-capable networking devices, not just limited to Juniper EX Series switches. VLAN 1 is commonly used as the default VLAN for management and default traffic, making it essential for initial switch configuration and communication within the network.

In practice, when you connect a device to a switch port and do not configure a specific VLAN, it will automatically belong to VLAN 1, unless the switch is specifically configured to place untagged traffic into a different VLAN. This default behavior facilitates ease of setup for basic networking requirements.

The other values provided do not represent the default VLAN ID for the EX Series switches, as they typically denote reserved or specific-purpose VLANs. For instance, VLAN ID 0 is typically used to indicate that the frame does not have a VLAN tag, while numbers such as 100 and 255 are commonly used for specific applications or custom VLAN configurations, but they are not the default settings for outgoing and incoming traffic on a new switch.