Use the following procedure to modify robustness of a VLAN.
From the navigation tree, double-click VLAN.
In the VLAN tree, double-click VLANs.
In the work area, click the Snoop tab.
In the table, In the VLAN row, double-click the cell in the Robustness column.
Type a numerical value for VLAN robustness.
Click Apply.