The IP address of the infrastructure node that is
currently the root node.
This object's value is 0.0.0.0 if this infrastructure
node is the root node. Else, this object's value is
the IP address of the root node.
Thus, the object's value is 0.0.0.0 if either one
of the following is true.
1) this infrastructure node offers WDS and is the
root node.
2) this infrastructure node offers WNS with the
value of cDot11csServiceType equal to 'rootWns'.
The object's value is the IP address of the root node
if the value of cDot11csServiceType is 'wns' for this
node.