3com S7906E Manuel De Montage
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[SwitchC-bgp] import-route ospf
4) Configure route redistribution on Switch B.
# Configure OSPF to redistribute routes from BGP on Switch B.
[SwitchB] ospf
[SwitchB-ospf-1] import-route bgp
# Display the OSPF routing table of Switch A.
[SwitchA] display ip routing-table
Routing Tables: Public
Destinations : 8 Routes : 8
Destination/Mask Proto Pre Cost NextHop Interface
10.1.1.0/24 O_ASE 150 1 11.2.1.1 Vlan100
10.2.1.0/24 O_ASE 150 1 11.2.1.1 Vlan100
10.3.1.0/24 O_ASE 150 1 11.2.1.1 Vlan100
10.4.1.0/24 O_ASE 150 1 11.2.1.1 Vlan100
11.2.1.0/24 Direct 0 0 11.2.1.2 Vlan100
11.2.1.2/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
5) # Configure summary route 10.0.0.0/8 on Switch B and advertise it.
[SwitchB-ospf-1] asbr-summary 10.0.0.0 8
# Display the OSPF routing table of Switch A.
[SwitchA] display ip routing-table
Routing Tables: Public
Destinations : 5 Routes : 5
Destination/Mask Proto Pre Cost NextHop Interface
10.0.0.0/8 O_ASE 150 2 11.2.1.1 Vlan100
11.2.1.0/24 Direct 0 0 11.2.1.2 Vlan100
11.2.1.2/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
Configuring an OSPF Stub Area
Network requirements
The following figure shows an AS is split into three areas, where all switches run OSPF. Switch A and
Switch B act as ABRs to forward routing information between areas. Switch D acts as the ASBR to
redistribute routes (static routes).
It is required to configure Area 1 as a Stub area, reducing LSAs to this area without affecting route
reachability.