0.0.0.0/32
10.1.1.0/24
10.2.1.0/24
10.3.1.0/24
10.4.1.0/24
11.2.1.0/24
11.2.1.0/32
11.2.1.2/32
11.2.1.255/32
127.0.0.0/8
127.0.0.0/32
127.0.0.1/32
127.255.255.255/32
224.0.0.0/4
224.0.0.0/24
255.255.255.255/32
5.
Configure route summarization:
# Configure route summarization on Switch B to advertise a summary route 10.0.0.0/8.
[SwitchB-ospf-1] asbr-summary 10.0.0.0 8
# Display the IP routing table on Switch A.
[SwitchA] display ip routing-table
Destination/Mask
0.0.0.0/32
10.0.0.0/8
11.2.1.0/24
11.2.1.0/32
11.2.1.2/32
11.2.1.255/32
127.0.0.0/8
127.0.0.0/32
127.0.0.1/32
127.255.255.255/32
224.0.0.0/4
224.0.0.0/24
255.255.255.255/32
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.
Configuring an OSPF stub area
Network requirements
Enable OSPF on all switches, and split the AS into three areas.
•
Configure Switch A and Switch B as ABRs to forward routing information between areas.
•
Direct 0
OSPF
150
OSPF
150
OSPF
150
OSPF
150
Direct 0
Direct 0
Direct 0
Direct 0
Direct 0
Direct 0
Direct 0
Direct 0
Direct 0
Direct 0
Direct 0
Destinations : 13
Proto
Pre
Direct 0
OSPF
150
Direct 0
Direct 0
Direct 0
Direct 0
Direct 0
Direct 0
Direct 0
Direct 0
Direct 0
Direct 0
Direct 0
0
127.0.0.1
1
11.2.1.1
1
11.2.1.1
1
11.2.1.1
1
11.2.1.1
0
11.2.1.2
0
11.2.1.2
0
127.0.0.1
0
11.2.1.2
0
127.0.0.1
0
127.0.0.1
0
127.0.0.1
0
127.0.0.1
0
0.0.0.0
0
0.0.0.0
0
127.0.0.1
Routes : 13
Cost
NextHop
0
127.0.0.1
2
11.2.1.1
0
11.2.1.2
0
11.2.1.2
0
127.0.0.1
0
11.2.1.2
0
127.0.0.1
0
127.0.0.1
0
127.0.0.1
0
127.0.0.1
0
0.0.0.0
0
0.0.0.0
0
127.0.0.1
88
InLoop0
Vlan100
Vlan100
Vlan100
Vlan100
Vlan100
Vlan100
InLoop0
Vlan100
InLoop0
InLoop0
InLoop0
InLoop0
NULL0
NULL0
InLoop0
Interface
InLoop0
Vlan100
Vlan100
Vlan100
InLoop0
Vlan100
InLoop0
InLoop0
InLoop0
InLoop0
NULL0
NULL0
InLoop0