Controlling how individual ports handle advertisements for new VLANs (CLI)
When GVRP is enabled on the switch, use the unknown-vlans command
to change the Unknown VLAN field for one or more ports.
Syntax:
interface<port-list>unknown-vlans [learn |<block>|<disable>]Changes the Unknown VLAN field to control how one or more ports handle advertisements. Use at either the Manager or interface context level for a port.
Changing the Unknown VLANs field
In the following example, the first command changes the configuration to Block, the second command displays the new configuration:
switch(config)#: interface 1-2 unknown-vlans block Switch(config)#: show gvrp GVRP support Maximum VLANs to support [256] : 256 Primary VLAN : DEFAULT_VLAN GVRP Enabled [No] : Yes Port Type | Unknown VLAN Join Leave Leaveall ---- --------- + ------------ ----- ----- -------- 1 10/100TX | Block 20 300 1000 2 10/100TX | Block 20 300 1000 3 10/100TX | Learn 20 300 1000 4 10/100TX | Learn 20 300 1000
When you enable GVRP on a switch, you have the per-port join-request options listed in the following table:
Options for handling unknown VLAN advertisements
| Unknown VLAN Mode | Operation |
|---|---|
Learn (the Default) |
Enables the port to become a member of any unknown VLAN for which it receives an advertisement. Allows the port to advertise other VLANs that have at least one other port on the same switch as a member. |
Block |
Prevents the port from joining any new dynamic VLANs for which it receives an advertisement. Allows the port to advertise other VLANs that have at least one other port as a member. |
Disable |
Causes the port to ignore and drop all GVRP advertisements it receives and prevents the port from sending any GVRP advertisements. |