Port-Based Virtual LANs (VLANs) and GVRP

GVRP

Converting a dynamic VLAN to a static VLAN and then executing the write memory command saves the VLAN in the startup-config file and makes it a permanent part of the switch’s VLAN configuration.

Within the same broadcast domain, a dynamic VLAN can pass through a device that is not GVRP-aware. This is because a hub or a switch that is not GVRP-ware will flood the GVRP (multicast) advertisement packets out all ports.

GVRP assigns dynamic VLANs as Tagged VLANs. To configure the VLAN as Untagged, you must first convert it to a static VLAN.

Rebooting a switch on which a dynamic VLAN exists deletes that VLAN. However, the dynamic VLAN re-appears after the reboot if GVRP is enabled and the switch again receives advertisements for that VLAN through a port configured to add dynamic VLANs.

By receiving advertisements from other devices running GVRP, the switch learns of static VLANs on those other devices and dynamically (automat­ ically) creates tagged VLANs on the links to the advertising devices.

Similarly, the switch advertises its static VLANs to other GVRP-aware devices, as well as the dynamic VLANs the switch has learned.

A GVRP-enabled switch does not advertise any GVRP-learned VLANs out of the port(s) on which it originally learned of those VLANs.

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