Configures the robustness variable.
<interface-vlan xmlns="urn:brocade.com:mgmt:brocade-interface"> <interface> <vlan> <name>1</name> <ip> <igmp xmlns="urn:brocade.com:mgmt:brocade-igmp-snooping"> <robustness-variable>3</robustness-variable> </igmp> </ip> </vlan> </interface> </interface-vlan>