20. Stub, a special area of OSPF configuration experiment
1. Stub analysis of special area
Whether to issue default routes stub filter LSA4 and LSA5ABR default. The seed cost value is 1. All routers in this area must be configured as stub, otherwise neighbors cannot play and cannot contain ASBR.
2. Experimental topology
3. 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 12.1.1.0 0.0.0.255 area 2
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 23.1.1.2 255.255.255.0router ospf 110
Router-id 2.2.2.2
Network 12.1.1.0 0.0.0.255 area 2
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 23.1.1.3 255.255.255.0router ospf 110
Router-id 3.3.3.3
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
Redistribute rip subnets
Network 34.1.1.0 0.0.0.255 area 1
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
Serial restart-delay 0
Router rip
Version 2
Network 5.0.0.0
Network 45.0.0.0
No auto-summary
4. Experimental verification.
Filter LSA4, LSA4
Before configuring stub
After configuring stub
ABR devolves three types of default routes
5. Modify the redistributed cost value. The default value is 1.
