What is the purpose of the first letter in a VLAN name?

• A. It identifies the department
• B. It identifies the VLAN number
• C. It identifies the data rate
• D. It identifies the security level

Answer: (D)

In many networks, VLAN names use a prefix to communicate policy attributes at a glance. When the first letter represents the security level, it lets administrators quickly understand how sensitive the traffic on that VLAN is and what controls should apply—such as which users or devices can access it and what monitoring or firewall rules are appropriate. The actual VLAN number is a separate numeric identifier, not coded by the name’s first character. Data rate isn’t conveyed through the name, and while other parts of the name might hint at department or function in some schemes, the first letter’s purpose is specifically to signal security level. So the best interpretation is that the initial letter identifies the security level.