Which technology allows VLAN information to be dynamically added to a trunk?

Which technology allows VLAN information to be dynamically added to a trunk?

• A. GVRP VLAN information
• B. LLDP-MED
• C. MSTP
• D. VTP

Answer: (A)

Dynamically adding VLAN information to a trunk is about automatically advertising and registering VLAN IDs so trunk links carry exactly the VLANs that exist in the network. GVRP (GARP VLAN Registration Protocol) does this by using GARP to register VLAN memberships across switches. When a switch learns about a VLAN via GVRP, it automatically adds that VLAN to its trunk configuration, allowing that VLAN’s traffic to be forwarded without manual trunk configuration. LLDP-MED is focused on discovering endpoints and applying policies (like QoS or powered devices) rather than dynamically propagating VLANs on trunks. MSTP deals with preventing loops across multiple VLANs, not dynamically advertising VLAN presence on trunks. VTP propagates VLAN definitions within Cisco environments, but it’s vendor-specific and not a universal mechanism for real-time dynamic trunk VLAN addition. Therefore, GVRP is the best fit for dynamically adding VLAN information to a trunk.

Dynamically adding VLAN information to a trunk is about automatically advertising and registering VLAN IDs so trunk links carry exactly the VLANs that exist in the network. GVRP (GARP VLAN Registration Protocol) does this by using GARP to register VLAN memberships across switches. When a switch learns about a VLAN via GVRP, it automatically adds that VLAN to its trunk configuration, allowing that VLAN’s traffic to be forwarded without manual trunk configuration.

LLDP-MED is focused on discovering endpoints and applying policies (like QoS or powered devices) rather than dynamically propagating VLANs on trunks. MSTP deals with preventing loops across multiple VLANs, not dynamically advertising VLAN presence on trunks. VTP propagates VLAN definitions within Cisco environments, but it’s vendor-specific and not a universal mechanism for real-time dynamic trunk VLAN addition. Therefore, GVRP is the best fit for dynamically adding VLAN information to a trunk.