Cisco 3845 Software Guide - Page 593

Chapter 29 Configuring IP Unicast Routing Configuring OSPF Configuring OSPF Network Types OSPF classifies different media into the three types of networks by default: • Broadcast networks (Ethernet, Token Ring, and FDDI) • Nonbroadcast multiaccess (NBMA) networks (Switched Multimegabit Data Service [SMDS], Frame Relay, and X.25) • Point-to-point networks (High-Level Data Link Control [HDLC], PPP) You can also configure network interfaces as either a broadcast or an NBMA network and as point-to point or point-to-multipoint, regardless of the default media type. Configuring OSPF for Nonbroadcast Networks Because many routers might be attached to an OSPF network, a designated router is selected for the network. If broadcast capability is not configured in the network, the designated router selection requires special configuration parameters. You need to configure these parameters only for devices that are eligible to become the designated router or backup designated router (in other words, routers with a nonzero router priority value). Beginning in privileged EXEC mode, follow these steps to configure routers that interconnect to nonbroadcast networks: Step 1 Step 2 Command configure terminal router ospf process-id Step 3 neighbor ip-address [priority number] [poll-interval seconds] Step 4 Step 5 Step 6 end show ip ospf [process-id] copy running-config startup-config Purpose Enter global configuration mode. Configure an OSPF routing process and enter router configuration mode. Specify an OSPF neighbor with neighbor parameters as required. • ip-address-Enter the interface IP address of the OSPF neighbor. • (Optional) priority number-Specify the router priority value of the nonbroadcast neighbor associated with the IP address. The range is 0 to 255; the default is 0. • (Optional) poll-interval seconds-Specify a number that represents the poll interval time (in seconds). This value should be much larger than the hello interval. The range is 0-4294967295; the default is 120 seconds (2 minutes). Return to privileged EXEC mode. Display OSPF-related information. (Optional) Save your entries in the configuration file. On point-to-multipoint, nonbroadcast networks, you then use the neighbor router configuration command to identify neighbors. Assigning a cost to a neighbor is optional. Configuring Network Types for OSPF Interfaces You can configure network interfaces as either broadcast or NBMA and as point-to point or point-to-multipoint, regardless of the default media type. OL-23400-01 Cisco ME 3800X and 3600X Switch Software Configuration Guide 29-27