The package, drcl.inet.protocol.OSPF, implements the link-state routing
protocol, OSPF v2, Open Shortest Path First routing protocol and follow
the RFC2328.
Constructor: Create new ospf6 interface structure
In our implementation, this function is called when OSPF receives
NEIGHBOR_UP event so that the state of interface is UP
Lookup lsa on request list of neighbor
This lookup is different from others, because this lookup is to find
the same LSA instance of different memory space
Class OSPF_Neighbor
The information exchanged with other adjacent nodes is described by a OSPF_Neighbor
data structure, which is bounded to a specific OSPF router interface.
ospf_send_hello
hello pkts are sent out each functing interface
*** not used, we use drcl.inet.core.Hello as underlying Hello service provider
ref: sec.