343neighboring interfaces. The smaller the hello interval, the faster the network convergence speedand the bigger the network load.If a router receives no hello packet from a neighbor within a period, which this period is calledthe dead interval, then it will declare the peer is down.After sending an LSA to its adjacency, a router waits for an acknowledgment from the adjacency.If no response is received after the retransmission interval elapses, the router will send the LSAagain. The retransmission interval must be longer than the round-trip time of the LSA.LSA delay timerEach LSA has an age in the local LSDB (incremented by one per second), but an LSA does notage on transmission. You must add an LSA delay time into the age time before transmission,which is important for low-speed networks.SPF timerWhenever the LSDB changes, an SPF calculation happens. If recalculations become frequent, alarge amount of resources will be occupied. You can adjust the SPF calculation interval and delaytime to protect networks from being overloaded due to frequent changes.GR timerIf a failure to establish adjacencies occurs during a GR, the switch will be in the GR process for along time. To avoid such cases, configure the GR timer for the switch to exit the GR process whenthe timer expires.OSPFv3 features supported• Basic features defined in RFC2740• OSPFv3 stub area• OSPFv3 multiprocess• OSPFv3 GRProtocols and standards• RFC 2740: OSPF for IPv6• RFC 2328: OSPF Version 2• RFC 5187: OSPFv3 Graceful RestartOSPFv3 configuration tasksEnabling OSPFv3Prerequisites• Make neighboring nodes accessible with each other at the network layer.
