Operation Manual – Routing ProtocolH3C S7500 Series Ethernet Switches Chapter 4 OSPF Configuration4-20The dead time on an interface must be at least four times of the Hello interval on thesame interface.After a router sends an LSA to a neighbor, it waits for an acknowledgement packetfrom the neighbor. If the router receives no acknowledgement packet from theneighbor within the retransmission interval, it retransmits the LSA to the neighbor.Follow these steps to configure OSPF timers:To do... Use the command... RemarksEnter system view system-view —Enter interface viewinterfaceinterface-typeinterface-number—Set the hello intervalon the interfaceospf timer hellosecondsOptionalBy default, p2p and broadcastinterfaces send Hello packetsevery 10 seconds; while p2mpand NBMA interfaces send Hellopackets every 30 seconds.Set the poll intervalon the NBMAinterfaceospf timer pollsecondsOptionalBy default, poll packets are sentevery 120 seconds.Set the dead time ofthe neighboringrouter on the interfaceospf timer deadsecondsOptionalBy default, the dead time for theOSPF neighboring router on ap2p or broadcast interface is 40seconds and that for the OSPFneighboring router on a p2mp orNBMA interface is 120 seconds.Set the interval atwhich the routerretransmits an LSA tothe neighboringrouter on the interfaceospf timer retransmitintervalOptional5 seconds by default.Note:Do not set an LSA retransmission interval that is too short. Otherwise, unnecessaryretransmission will occur. LSA retransmission interval must be greater than the roundtrip time of a packet between two routers.4.7.3 Configuring the LSA transmission delayFollow these steps to configure the LSA transmission delay:
