4-20OSPF Network Adjustment and OptimizationYou can adjust and optimize an OSPF network in the following aspects:z By changing the OSPF packet timers, you can adjust the convergence speed of the OSPF networkand the network load brought by OSPF packets. On some low-speed links, you need to considerthe delay experienced when the interfaces transmit LSAs.z By Adjusting SPF calculation interval, you can mitigate resource consumption caused by frequentnetwork changes.z In a network with high security requirements, you can enable OSPF authentication to enhanceOSPF network security.z In addition, OSPF supports network management. You can configure the binding of the OSPF MIBwith an OSPF process and configure the Trap message transmission and logging functions.Configuration PrerequisitesBefore adjusting and optimizing an OSPF network, perform the following tasks:z Configuring the network layer addresses of interfaces so that the adjacent nodes are reachable toeach other at the network layerz Configuring basic OSPF functionsConfiguring OSPF TimersThe Hello intervals for OSPF neighbors must be consistent. The value of Hello interval is in inverseproportion to route convergence speed and network load.The dead time on an interface must be at least four times of the Hello interval on the same interface.After a router sends an LSA to a neighbor, it waits for an acknowledgement packet from the neighbor. Ifthe router receives no acknowledgement packet from the neighbor within the retransmission interval, itretransmits the LSA to the neighbor.Follow these steps to configure OSPF timers:To do... Use the command... RemarksEnter system view system-view —Enter interface view interface interface-typeinterface-number —Configure the hello intervalon the interface ospf timer hello secondsOptionalBy default, p2p and broadcastinterfaces send Hello packetsevery 10 seconds; while p2mp andNBMA interfaces send Hellopackets every 30 seconds.Configure the poll interval onthe NBMA interface ospf timer poll seconds Optional40 seconds by defaultConfigure the dead time ofthe neighboring router onthe interfaceospf timer dead secondsOptionalBy default, the dead time for theOSPF neighboring router on a p2por broadcast interface is 40seconds and that for the OSPFneighboring router on a p2mp orNBMA interface is 120 seconds.
