3Com Switch 8800 Advanced Software V5 Configuration Guide

OSPF Configuration Examples 341
Configuring an OSPF
Stub Area
Network requirements
The following figure shows an AS is split into three areas, where all switches run
OSPF. SwitchA and SwitchB act as ABRs to forward routing information between
areas. SwitchD acts as the ASBR, redistributing routes (static routes).
It is required to configure Area1 as a Stub area, reducing LSAs to this area without
affecting route reachability.
Network diagram
Figure 104 Network diagram for OSPF Stub area configuration
Configuration procedure
1 Configure IP addresses for interfaces (omitted).
2 Configure OSPF basic functions (in the previous example).
3 Configure SwitchD to redistribute static routes.
[SwitchD] ip route-static 200.0.0.0 8 null 0
[SwitchD] ospf
[SwitchD-ospf-1] import-route static
[SwitchD-ospf-1] quit
# Display ABR/ASBR information on SwitchC
[SwitchC] display ospf abr-asbr
OSPF Process 1 with Router ID 192.168.1.2
Routing Table to ABR and ASBR
type Destination Area Cost Nexthop Rttype
Intra 192.168.1.1 0.0.0.1 1 192.168.1.1 ABR
Inter 192.168.2.2 0.0.0.1 3 192.168.1.1 ASBR
# Display OSPF routing table information on SwitchC.
[SwitchC] display ospf routing
OSPF Process 1 with Router ID 192.168.1.2
Routing Tables
Routing for Network
Destination Cost type NextHop AdvRouter Area
172.16.1.0/24 1 Stub 172.16.1.1 192.168.1.2 0.0.0.1
172.17.1.0/24 4 Inter 192.168.1.1 192.168.1.1 0.0.0.1
192.168.0.0/24 2 Inter 192.168.1.1 192.168.1.1 0.0.0.1
Area 0
Area 1
Stub
Area 2
Switch C
Vlan-int100
192.168.0.2/24
Vlan-int100
192.168.0.1/24
Vlan-int300
172.16.1.1/24
Vlan-int200
192.168.1.2/24
Switch B
Vlan-int200
192.168.2.1/24
Vlan-int200
192.168 .2.2/24
Switch A
Vlan-int200
192.168.1.1/24
Vlan-int300
172.17.1.1/24
Switch D
ASBR