What is the maximum number of unique VLAN IDs available?

The maximum number of unique VLAN IDs is defined by the IEEE 802.1Q standard. The standard specifies a 12-bit field for the VLAN Identifier (VID) within the Ethernet frame's VLAN tag. A 12-bit field can represent 2^12, or 4096, unique values. This creates a theoretical range of VLAN IDs from 0 to 4095. While IDs 0 and 4095 are reserved for specific functions and are generally not usable for user-configured VLANs, the total address space defined by the 12-bit field is 4096.

A. 2048 is the result of an 11-bit field (2^11), which is not the size of the IEEE 802.1Q VID field.

B. 3192 is an arbitrary value with no technical correlation to the IEEE 802.1Q VLAN standard.

D. 16384 is the result of a 14-bit field (2^14), which is incorrect for the standard VLAN ID.

1. IEEE Std 802.1Q-2018

IEEE Standard for Local and metropolitan area networks—Bridges and Bridged Networks.

Section 9.6

"VLAN tag format": This section explicitly defines the VLAN Identifier (VID) as a 12-bit field. The text states

"The VLAN Identifier (VID) is a 12-bit field that uniquely identifies the VLAN to which the frame belongs." This directly supports the calculation of 2^12 = 4096 possible IDs.

2. Ericsson

"Layer 2 Switching and VPLS Configuration Guide" for Smart Services Router (SSR) running IPOS.

Chapter: "VLANs"

Section: "VLAN Tagging": The documentation states

"The VLAN ID is a 12-bit field

which specifies the VLAN to which the frame belongs. The range of VLAN IDs is 0 to 4095." This official vendor documentation confirms the 4096 total IDs.

3. University of Cambridge

Computer Laboratory

"L32: Virtual LANs (VLANs)" Course Material.

Slide 5

"802.1Q VLAN Tag": The course slide deck illustrates the 802.1Q tag format and explicitly labels the VLAN ID (VID) field as "12 bits

4096 VLANs possible." This serves as a reputable academic source confirming the total number.