690 BigIron RX Series Configuration Guide53-1001986-01Configuring OSPF25Configuring an OSPF non-broadcast interfaceOSPF routers generally use broadcast packets to establish neighbor relationships and broadcastroute updates on Ethernet and virtual routing interfaces (ves). Beginning with BigIron RX softwarereleases 02.3.00, you can configure an interface to send OSPF unicast packets rather thanbroadcast packets to its neighbor by configuring non-broadcast multi-access (NBMA) networks.NBMA networks are similar to broadcast networks except the packets are sent as unicast. This typeof network can be useful in situations where multicast traffic is not feasible (for example when afirewall does not allow multicast packets).You configure NBMAs on an interface. The routers at the other end of that interface must have anon-broadcast neighbor configured. There is no restriction on the number of routers sharing anon-broadcast interface (for example, through a hub or switch).To configure NBMA on an interface, do the following.1. Create an OSPF area on an interface, then enable NBMA on that interface.BigIron RX(config)# int ve 20BigIron RX(config-vif-20)# ip ospf area 0BigIron RX(config-vif-20)# ip ospf network non-broadcastBigIron RX(config-vif-20)# exitSyntax: [no] ip ospf network non-broadcast2. Then under the router OSPF level, specify the IP address of the neighbor in the OSPFconfiguration. The non-broadcast interface configuration must be done on the OSPF routers onboth ends of the link.For example, the following commands configure VE 20 as a non-broadcast interface.The following commands specify 1.1.20.1 as an OSPF neighbor address. The address specifiedmust be in the same sub-net as a non-broadcast interface.BigIron RX(config)# router ospfBigIron RX(config-ospf-router)# neighbor 1.1.20.1Syntax: neighbor MD5 Authentication Wait Time This parameter determines when a newly configured MD5 authenticationkey is valid. This parameter provides a graceful transition from one MD5key to another without disturbing the network. All new packets transmittedafter the key activation wait time interval use the newly configured MD5Key. OSPF packets that contain the old MD5 key are accepted for up to fiveminutes after the new MD5 key is in operation.The range for the key activation wait time is from 0 – 14400 seconds. Thedefault value is 300 seconds.Hello Interval The length of time between the transmission of hello packets. The range is1 – 65535 seconds. The default is 10 seconds. On NBMA, the default is30 seconds.Retransmit Interval The interval between the re-transmission of link state advertisements torouter adjacencies for this interface. The range is 0 – 3600 seconds. Thedefault is 5 seconds.Transmit Delay The period of time it takes to transmit Link State Update packets on theinterface. The range is 0 – 3600 seconds. The default is 1 second.
