Example 3: Summarizing Routes - IBM RackSwitch G8000 Application Manual

Example 3: Summarizing Routes

© Copyright IBM Corp. 2011
By default, ABRs advertise all the network addresses from one area into another
area. Route summarization can be used for consolidating advertised addresses and
reducing the perceived complexity of the network.
If network IP addresses in an area are assigned to a contiguous subnet range, you
can configure the ABR to advertise a single summary route that includes all
individual IP addresses within the area.
The following example shows one summary route from area 1 (stub area) injected
into area 0 (the backbone). The summary route consists of all IP addresses from
36.128.192.0 through 36.128.254.255 except for the routes in the range
36.128.200.0 through 36.128.200.255.
Note: OSPFv2 supports IPv4 only. IPv6 is supported in OSPFv3 (see
Implementation in IBM N/OS" on page
Figure 32. Summarizing Routes
Note: You can specify a range of addresses to prevent advertising by using the
hide option. In this example, routes in the range 36.128.200.0 through
36.128.200.255 are kept private.
Use the following procedure to configure OSPF support as shown in
1. Configure IP interfaces for each network which will be attached to OSPF areas.
RS G8000(config)# interface ip 1
RS G8000(config-ip-if)# ip address 10.10.7.1
RS G8000(config-ip-if)# ip netmask 255.255.255.0
RS G8000(config-ip-if)# enable
RS G8000(config-ip-if)# exit
RS G8000(config)# interface ip 2
RS G8000(config-ip-if)# ip address 36.128.192.1
RS G8000(config-ip-if)# ip netmask 255.255.255.0
RS G8000(config-ip-if)# enable
RS G8000(config-ip-if)# exit
2. Enable OSPF.
RS G8000(config)# router ospf
RS G8000(config-router-ospf)# enable
3. Define the backbone.
RS G8000(config-router-ospf)# area 0 area-id 0.0.0.0
RS G8000(config-router-ospf)# area 0 type transit
RS G8000(config-router-ospf)# area 0 enable
279).
Chapter 22. OSPF
"OSPFv3
Figure 32:
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