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11-2 neighbor ip-address cost costSyntax Description:
Purpose: To configure the cost of an OSPF neighbor on a point-to-multipoint network. Initial Cisco IOS Software Release: 11.3 Configuration Example: Modifying the Cost of an OSPF Neighbor on a Point-to-Multipoint InterfaceThe cost to reach an OSPF neighbor is, by default, the bandwidth of the network connecting the two neighbors divided into 100,000,000. In Figure 11-5, the bandwidth of the Frame Relay link is 2048 kbps. Therefore, the OSPF cost of the Frame Relay interfaces is 48 (100,000,000/2,048,000). The cost option of the neighbor command can be used to change the cost to reach the neighbor. The interface command ip ospf cost (see Section 19-3) can also be used to change this cost. The neighbor cost command can only be used on point-to-multipoint interfaces. The listing that follows the figure shows the configurations of the Frame Relay switch and Routers A and B. Figure 11-5. The Default Cost of an OSPF Interface Is 100,000,000/(Interface Bandwidth in bps). The neighbor cost Command Can Be Used to Modify the Interface Cost
Frame Switch hostname frame-relay ! frame-relay switching ! interface Serial1/0 no ip address no ip directed-broadcast encapsulation frame-relay no ip mroute-cache no fair-queue clockrate 2015232 frame-relay lmi-type ansi frame-relay intf-type dce frame-relay route 101 interface Serial1/1 110 frame-relay route 102 interface Serial1/2 120 frame-relay route 103 interface Serial1/3 130 ! interface Serial1/1 no ip address no ip directed-broadcast encapsulation frame-relay clockrate 2015232 frame-relay lmi-type ansi frame-relay intf-type dce frame-relay route 110 interface Serial1/0 101 frame-relay route 112 interface Serial1/2 121 frame-relay route 113 interface Serial1/3 131 ________________________________________________________________________ Router A interface Loopback0 ip address 1.1.1.1 255.255.255.255 ! interface Serial0/0 bandwidth 2048 ip address 10.1.1.1 255.255.255.252 encapsulation frame-relay ip ospf network point-to-multipoint frame-relay map ip 10.1.1.2 101 broadcast no frame-relay inverse-arp frame-relay lmi-type ansi ! router ospf 1 network 1.1.1.1 0.0.0.0 area 1 network 10.1.1.0 0.0.0.3 area 0 ________________________________________________________________ Router B interface Loopback0 ip address 2.2.2.2 255.255.255.255 ! interface Serial0 bandwidth 2048 ip address 10.1.1.2 255.255.255.252 encapsulation frame-relay ip ospf network point-to-multipoint frame-relay map ip 10.1.1.1 110 broadcast no frame-relay inverse-arp frame-relay lmi-type ansi ! router ospf 1 network 2.2.2.2 0.0.0.0 area 2 network 10.1.1.0 0.0.0.3 area 0 The interface command ip ospf network point-to-multipoint (see Section 19-15) is used because the neighbor cost command will work only on a point-to-multipoint interface. Display the IP routing table on Router B to see the cost of reaching the loopback network on Router A. rtrB# show ip route Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default U - per-user static route, o - ODR Gateway of last resort is not set 1.0.0.0/32 is subnetted, 1 subnets O IA 1.1.1.1 [110/49] via 10.1.1.1, 00:22:11, Serial0 2.0.0.0/32 is subnetted, 1 subnets C 2.2.2.2 is directly connected, Loopback0 172.16.0.0/24 is subnetted, 1 subnets C 172.16.1.0 is directly connected, Ethernet0 10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks C 10.1.1.0/30 is directly connected, Serial0 O 10.1.1.1/32 [110/10] via 10.1.1.1, 00:22:11, Serial0 The cost is the sum of the cost of the loopback interface (1) and the cost of the Frame Relay link (48) for a total cost of 49. Modify the configuration on Router B to change the cost of the Frame Relay link to 10. Router B router ospf 1 network 2.2.2.2 0.0.0.0 area 2 network 10.1.1.0 0.0.0.3 area 0 neighbor 10.1.1.1 cost 10 VerificationVerify that the cost of the Frame Relay interface, as seen by Router B, has changed to 10. rtrB# show ip route Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, * - candidate default U - per-user static route, o - ODR Gateway of last resort is not set 1.0.0.0/32 is subnetted, 1 subnets O IA 1.1.1.1 [110/11] via 10.1.1.1, 00:01:49, Serial0 2.0.0.0/32 is subnetted, 1 subnets C 2.2.2.2 is directly connected, Loopback0 172.16.0.0/24 is subnetted, 1 subnets C 172.16.1.0 is directly connected, Ethernet0 10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks C 10.1.1.0/30 is directly connected, Serial0 O 10.1.1.1/32 [110/10] via 10.1.1.1, 00:01:49, Serial0 Troubleshooting
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