When you assign an IPspace to a vFiler unit, you must ensure that the vFiler unit has a unique IP address within that IPspace. After you assign an IPspace to a vFiler unit, you cannot change the IPspace without destroying the vFiler unit.
An IPspace can contain multiple vFiler units. However, a vFiler unit can belong only to one IPspace. A vFiler unit in one IPspace can have the same IP address as a vFiler unit in a different IPspace.
Each vFiler unit must have one IP address on the interface that leads to the default gateway of the assigned IPspace. This requirement ensures that the vFiler unit is reachable from within the IPspace.