Netgear XCM89UP Command Line Interface CLI User Manual Software Version 11.x - Page 773

M5300, M6100, and M7100 Series ProSAFE Managed Switches nsf helper strict-lsa-checking (OSPF) The restarting router is unable to react to topology changes. In particular, the restarting router will not immediately update its forwarding table; therefore, a topology change may introduce forwarding loops or black holes that persist until the graceful restart completes. By exiting the graceful restart on a topology change, a router tries to eliminate the loops or black holes as quickly as possible by routing around the restarting router. A helpful neighbor considers a link down with the restarting router to be a topology change, regardless of the strict LSA checking configuration. Use this command to require that an OSPF helpful neighbor exit helper mode whenever a topology change occurs. Default Format Modes Enabled. nsf [ietf] helper strict-lsa-checking OSPF Router Configuration Parameter ietf Description This keyword is accepted but not required. no nsf [ietf] helper strict-lsa-checking Use this command to allow OSPF to continue as a helpful neighbor in spite of topology changes. Default Format Modes Enabled. nsf [ietf] helper strict-lsa-checking OSPF Router Configuration OSPFv2 Stub Router Commands max-metric router-lsa (OSPFv2 Router Configuration) To configure OSPF to enter stub router mode, use this command in Router OSPF Global Configuration mode. When OSPF is in stub router mode, as defined by RFC 3137, OSPF sets the metric in the nonstub links in its router LSA to LsInfinity. Other routers therefore compute very long paths through the stub router, and prefer any alternate path. Doing so eliminates all transit traffic through the stub router, when alternate routes are available. Stub router mode is useful when adding or removing a router from a network or to avoid transient routes when a router reloads. You can administratively force OSPF into stub router mode. OSPF remains in stub router mode until you take OSPF out of stub router mode. Alternatively, you can configure OSPF to start in stub router mode for a configurable period of time after the router boots up. Routing Commands 773