1-27z P2P: When the link layer protocol is PPP, LAPB, HDLC, or POS, OSPF considers the network typeas P2P by default.You can change the network type of an interface as needed. For example:z When an NBMA network becomes fully meshed through address mapping, namely, when any tworouters in the network have a direct virtual link in between, you can change the network type tobroadcast, without manually configuring the neighbors.z When some routers in the broadcast network do not support multicast, you can change the networktype to NBMA.z An NBMA network is fully meshed, which means any two routers in the NBMA network have adirect virtual link for communication. If direct connections are not available between some routers,the type of interfaces associated should be configured as P2MP, or as P2P for interfaces with onlyone neighbor.If two interfaces on a link are both configured as the broadcast, NBMA or P2MP type, they cannotestablish a neighbor relationship unless they are on the same network segment.PrerequisitesBefore configuring OSPF network types, you have configured:z IP addresses for interfaces, making neighboring nodes accessible with each other at network layer.z OSPF basic functions.Configuring the OSPF Network Type for an Interface as BroadcastFollow these steps to configure the OSPF network type for an interface as broadcast:To do… Use the command… RemarksEnter system view system-view —Enter interface view interface interface-typeinterface-number —Configure the OSPF networktype for the interface asbroadcastospf network-typebroadcastRequiredBy default, the network type of aninterface depends on the linklayer protocol.Configure a DR priority for theinterface ospf dr-priority priority OptionalThe default DR priority is 1.Configuring the OSPF Network Type for an Interface as NBMAAfter configuring the network type of an interface as NBMA, you need to make some specialconfigurations.Because NBMA interfaces cannot find neighbors via broadcasting Hello packets, you need to specifyneighbors and neighbor DR priorities. (A DR priority of 0 means the router does not have the DRelection right; a DR priority greater than 0 means the router has the DR election right).
