OSPF Network failure handling case

OSPF Network failure handling cases

Network topology 11.1 is shown. Network planning is as follows:

N R1 and R2 's interconnected addresses are: 10.0.0.0/30;R2 and R3 's interconnected address: 20.0.0.0/30,R3 and R4 are connected to: 30.0.0.0/30;R4 and R1;

n Use the Loopback0 interface address of the router as the loopback0:2.2.2.2/32,r3 of the ROUTE-ID,R1 loopback0:1.1.1.1/32,r2 loopback0:3.3.3.3/ The loopback0:4.4.4.4/32 of 32,R4;

n using the router's loopback interface to simulate the client host address, the R3 router with a total of four network segments of the host are: 192.168.0.0/24, 192.168.1.0/24, 192.168.2.0/24, 192.168.3.0/24.

650) this.width=650; "Style=" background-image:none; border-bottom:0px; border-left:0px; padding-left:0px; padding-right:0px; border-top:0px; border-right:0px; padding-top:0px "title=" clip_image002 "border=" 0 "alt=" clip_image002 "src=" http://s3.51cto.com/wyfs02/M01/77/89/ Wkiol1zpe7bztbhtaaasxskjljy498.jpg "" 244 "height=" 119 "/>

Figure 11.1 Benet Company network topology diagram

After configuring the routing summary on the ABR, it is found that the R1 router can still learn the detail route, which causes the packets to be forwarded only through the detailed route to form load balancer. Please review the configuration to resolve the issue.

R1 Configuration

Router OSPF 1

Router-id 1.1.1.1

Network 1.1.1.1 0.0.0.0 Area 0

Network 10.0.0.0 0.0.0.3 Area 0

Network 40.0.0.0 0.0.0.3 Area 0

R2 Configuration

Router OSPF 1

Router-id 2.2.2.2

Area 1 Range 192.168.0.0 255.255.252.0

Network 2.2.2.2 0.0.0.0 Area 0

Network 10.0.0.0 0.0.0.3 Area 0

Network 20.0.0.0 0.0.0.3 Area 1

R3 Configuration

Router OSPF 1

Router-id 3.3.3.3

Network 3.3.3.3 0.0.0.0 Area 1

Network 20.0.0.0 0.0.0.3 Area 1

Network 30.0.0.0 0.0.0.3 Area 1

Network 192.168.0.0 0.0.0.255 Area 1

Network 192.168.1.0 0.0.0.255 Area 1

Network 192.168.2.0 0.0.0.255 Area 1

Network 192.168.3.0 0.0.0.255 Area 1

R4 Configuration

Router OSPF 1

Router-id 4.4.4.4

Network 4.4.4.4 0.0.0.0 Area 0

Network 30.0.0.0 0.0.0.3 Area 1

Network 40.0.0.0 0.0.0.3 Area 0

First, look at the R1 routing table as shown below:

192.168.0.0/32 is subnetted, 1 subnets

O IA 192.168.0.1 [110/3] via 40.0.0.1, 00:25:05, fastethernet1/0

192.168.1.0/32 is subnetted, 1 subnets

O IA 192.168.1.1 [110/3] via 40.0.0.1, 00:25:05, fastethernet1/0

192.168.2.0/32 is subnetted, 1 subnets

O IA 192.168.2.1 [110/3] via 40.0.0.1, 00:25:05, fastethernet1/0

192.168.3.0/32 is subnetted, 1 subnets

O IA 192.168.3.1 [110/3] via 40.0.0.1, 00:25:05, fastethernet1/0

O IA 192.168.0.0/22 [110/3] via 10.0.0.2, 00:25:05, fastethernet0/0

By looking at the routing table, we discovered that the R1 router learned detailed routing and detailed routing, and then carefully observed that the next hop in the routing table found that R2 was releasing the summarized route, and the detail route was R4 released. This shows that the fault is caused by the rollup configuration of the R4 router.

Check the configuration of the R4 router and find that the routing summary is not configured, causing the routing table to be able to learn the detailed route before the summary, resulting in packets being forwarded only from the detail route;

Configure the area 1 range 192.168.0.0 255.255.252.0 command on the R4 to implement the route rollup, review the routing table of the R1 router again, R1 has learned the routing summary and implemented load sharing as follows:

O IA 192.168.0.0/22 [110/3] via 40.0.0.1, 00:00:10, fastethernet1/0

[110/3] via 10.0.0.2, 00:00:10, fastethernet0/0

OSPF Network failure handling case