In many OSPF networks, OSPF routers remove a restarting OSPF router from the network topology, if the router is restarted. This action causes all OSPF routers to re-converge and route around the restarting router. The OSPF Graceful Restart feature is an OSPF enhancement to allow an OSPF router to stay on the forwarding path when the software is restarting.
This feature is documented under RFC 3623 for OSPFv2 (IPv4) and RFC 5187 for OSPFv3 (IPv6). The switch software supports only helper mode for both OSPFv2 and OSPFv3 protocols.