24. Two-way redistribution of multi-processes in irregular areas of OSPF configuration experiments
1. Experimental Topology
After OSPF is configured as shown in the topology, R5 in area2 does not have routes to area3, area0, and area1 because there is an area1 between area2 and area0. For this reason, we start two OSPF routing processes on R4, announce area1 and area2 respectively, and redistribute each other in the OSPF process.
2. Experimental configuration
R1 configuration
Interface Loopback0
Ip address 1.1.1.1 255.255.255.0
Interface Serial0/0
Ip address 12.1.1.1 255.255.255.0
Router ospf 110
Router-id 1.1.1.1
Network 1.1.1.0 0.0.0.255 area 3
Network 12.1.1.0 0.0.0.255 area 3
R2 configuration
Interface Loopback0
Ip address 2.2.2.2 255.255.255.0
Interface Serial0/0
Ip address 12.1.1.2 255.255.255.0
Interface Serial0/1
Ip address 23.1.1.2 255.255.255.0
Router ospf 110
Router-id 2.2.2.2
Network 2.2.2.0 0.0.0.255 area 0
Network 12.1.1.0 0.0.0.255 area 3
Network 23.1.1.0 0.0.0.255 area 0
R3 configuration
Interface Loopback0
Ip address 3.3.3.3 255.255.255.0
Interface Serial0/0
Ip address 34.1.1.3 255.255.255.0
Interface Serial0/1
Ip address 23.1.1.3 255.255.255.0
Router ospf 110
Router-id 3.3.3.3
Network 3.3.3.0 0.0.0.255 area 0
Network 23.1.1.0 0.0.0.255 area 0
Network 34.1.1.0 0.0.0.255 area 1
R4 configuration
Interface Loopback0
Ip address 4.4.4.4 255.255.255.0
Interface Serial0/0
Ip address 34.1.1.4 255.255.255.0
Interface Serial0/1
Ip address 45.1.1.4 255.255.255.0
Router ospf 110
Router-id 4.4.4.4
Log-adjacency-changes
Network 4.4.4.0 0.0.0.255 area 1
Network 34.1.1.0 0.0.0.255 area 1
Network 45.1.1.0 0.0.0.255 area 2
R5 configuration
Interface Loopback0
Ip address 5.5.5.5 255.255.255.0
Interface Serial0/1
Ip address 45.1.1.5 255.255.255.0
Router ospf 110
Router-id 5.5.5.5
Log-adjacency-changes
Network 5.5.5.0 0.0.0.255 area 2
Network 45.1.1.0 0.0.0.255 area 2
3. Configure OSPF multi-process redistribution
At this point, neither R1 nor R5 has routes to each other. We modified the configuration of OSPF on R4 as follows
Router ospf 110
Router-id 4.4.4.4
Log-adjacency-changes
Redistribute ospf 100 subnets
Network 4.4.4.0 0.0.0.255 area 1
Network 34.1.1.0 0.0.0.255 area 1
Router ospf 100
Router-id 4.4.4.40
Log-adjacency-changes
Redistribute ospf 110 subnets
Network 45.1.1.0 0.0.0.255 area 2
