DELL N3000 User Manual

Configuring OSPF and OSPFv3

Flood blocking cannot be enabled on virtual interfaces. While the feature 

could be allowed on virtual interfaces, it is less likely to be used on a virtual 

interface, since virtual interfaces are created specifically to allow flooding 

between two backbone routers. So the option of flood blocking on virtual 

interfaces is not supported.
See "Configuring Flood Blocking" on page 1195 for a configuration example.