Patent ID: 9503357
Filing Date: 2016-11-22
CPC Classification: H04L

Claim Text:
1. A method in an Open Shortest Path First (OSPF) hub router to limit an amount of topology and reachability information that is advertised to one or more OSPF spoke routers of a stub site that are in a same routing area as the OSPF hub router, wherein each of the one or more OSPF spoke routers are not within a Stub Area (SA) or a Not-So-Stubby Area (NSSA), the method comprising: performing a database exchange process, comprising: transmitting, to each of the one or more OSPF spoke routers that are connected to the OSPF hub router over one of one or more stub interfaces, only a single Stub-Site Router-Link State Advertisement (Router-LSA) that describes a single stub link for a default route or one or more stub links corresponding to aggregate routes of the same routing area, wherein the single Stub-Site Router-LSA does not describe each of the directly connected links of the OSPF hub router; transmitting, over one or more non-stub interfaces but not over the one or more stub interfaces, an OSPF Type 1 Router-LSA, wherein the OSPF Type 1 Router-LSA includes more link information than the single Stub-Site Router-LSA transmitted over the one or more stub interfaces and describes each of the directly connected links of the OSPF hub router; receiving, over the one or more stub interfaces, a first set of one or more LSAs: receiving, over the one or more non-stub interfaces, a second set of one or more LSAs; installing the first set of LSAs but not the second set of LSAs in a Stub-Site Link State Database (LSDB) that is scoped only to the stub site, wherein each LSA of the first set of LSAs includes a Stub Site bit identifying the LSA as being a Stub-Site LSA; and installing the second set of LSAs but not the first set of LSAs in an Area LSDB.