102
0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
10.1.1.0/24 OSPF 150 1 11.2.1.1 Eth1/1
10.2.1.0/24 OSPF 150 1 11.2.1.1 Eth1/1
10.3.1.0/24 OSPF 150 1 11.2.1.1 Eth1/1
10.4.1.0/24 OSPF 150 1 11.2.1.1 Eth1/1
11.2.1.0/24 Direct 0 0 11.2.1.2 Eth1/1
11.2.1.0/32 Direct 0 0 11.2.1.2 Eth1/1
11.2.1.2/32 Direct 0 0 127.0.0.1 InLoop0
11.2.1.255/32 Direct 0 0 11.2.1.2 Eth1/1
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0
224.0.0.0/4 Direct 0 0 0.0.0.0 NULL0
224.0.0.0/24 Direct 0 0 0.0.0.0 NULL0
255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0
5.
Configure route summarization:
# Configure route summarization on Router B to advertise a single route 10.0.0.0/8.
[RouterB-ospf-1] asbr-summary 10.0.0.0 8
# Display the IP routing table on Router A.
[RouterA] display ip routing-table
Destinations : 13 Routes : 13
Destination/Mask Proto Pre Cost NextHop Interface
0.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
10.0.0.0/8 OSPF 150 2 11.2.1.1 Eth1/1
11.2.1.0/24 Direct 0 0 11.2.1.2 Eth1/1
11.2.1.0/32 Direct 0 0 11.2.1.2 Eth1/1
11.2.1.2/32 Direct 0 0 127.0.0.1 InLoop0
11.2.1.255/32 Direct 0 0 11.2.1.2 Eth1/1
127.0.0.0/8 Direct 0 0 127.0.0.1 InLoop0
127.0.0.0/32 Direct 0 0 127.0.0.1 InLoop0
127.0.0.1/32 Direct 0 0 127.0.0.1 InLoop0
127.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0
224.0.0.0/4 Direct 0 0 0.0.0.0 NULL0
224.0.0.0/24 Direct 0 0 0.0.0.0 NULL0
255.255.255.255/32 Direct 0 0 127.0.0.1 InLoop0
The output shows that routes 10.1.1.0/24, 10.2.1.0/24, 10.3.1.0/24 and 10.4.1.0/24 are
summarized into a single route 10.0.0.0/8.
OSPF stub area configuration example
Network requirements
•
Enable OSPF on all routers, and split the AS into three areas.
•
Configure Router A and Router B as ABRs to forward routing information between areas.