This attribute is associated with the Route Reflector. It indicates the
router-id of the originator of a route in the local AS. When the
Route Reflector distributes a learned IBGP route to other IBGP
speakers, the value of this attribute in the learned route is used if
one is present; othewise, the Route Reflector's router-id is used. A
value of 0.0.0.0 indicates this Bgp instance is not a Route Reflector.