Open Shortest Path First (OSPFv2 and OSPFv3) | 701period. You reconfigure OSPFv3 graceful restart to a “restarting-only” role when you enable thehelper-reject role on an interface. OSPFv3 supports the helper-reject role on a per-interface basis.Configuring helper-reject role on an OSPFv2 router or OSPFv3 interface enables the restarting-onlyrole globally on the router or locally on the interface. In a helper-reject role, OSPF does not participatein the graceful restart of an adjacent OSPFv2/v3 router.If multiple OSPF interfaces provide communication between two routers, after you configurehelper-reject on one interface, all other interfaces between the two routers behave as if they are in thehelp-reject role.• OSPFv2 and OSPFv3 support planned-only and/or unplanned-only restarts. The default is support forboth planned and unplanned restarts.A planned restart occurs when you enter the redundancy force-failover rpm command to force theprimary RPM to switch to the backup RPM. During a planned restart, OSPF sends out a Grace LSAbefore the system switches over to the backup RPM.An unplanned restart occurs when an unplanned event causes the active RPM to switch to the backupRPM, such as when an active process crashes, the active RPM is removed, or a power failure happens.During an unplanned restart, OSPF sends out a Grace LSA when the backup RPM comes online.To display the configuration values for OSPF graceful restart, enter the following commands:• For OSPFv2: show run ospf• For OSPFv3: show run ospf and show ipv6 ospf database database-summaryFast Convergence (OSPFv2, IPv4 only)Fast Convergence allows you to define the speeds at which LSAs are originated and accepted, and reduceOSPFv2 end-to-end convergence time. FTOS enables you to accept and originate LSAa as soon as they areavailable to speed up route information propagation.Note that the faster the convergence, the more frequent the route calculations and updates. This will impactCPU utilization and may impact adjacency stability in larger topologies.Multi-Process OSPF (OSPFv2, IPv4 only)Multi-Process OSPF is supported on platforms c e and s with FTOS version 7.8.1.0 and later,and is supported on OSPFv2 with IPv4 only.Multi-Process OSPF allows multiple OSPFv2 processes on a single router. Multiple OSPFv2 processesallow for isolating routing domains, supporting multiple route policies and priorities in different domains,and creating smaller domains for easier management.• The E-Series supports up to 28 OSPFv2 processes.• The C-Series supports up to 6 OSPFv2 processes.• The S-Series supports up to 3 OSPFv2 processes.
