BSCI communicating success, not to name earning your CCNP, crapper become downbound to your OSPF line account skills. There are a some assorted commands and situations you requirement to be primed for, and digit of these alive info is the comely ingest of the summary-address command.
The summary-address bidding should be utilised on an ASBR in meet to repeat routes that are existence injected into the OSPF field via redistribution. In the mass example, quaternary routes are existence redistributed into OSPF on R1, making R1 an ASBR.
interface Loopback16
ip come 16.16.16.16 255.0.0.0
!
programme Loopback17
ip come 17.17.17.17 255.0.0.0
!
programme Loopback18
ip come 18.18.18.18 255.0.0.0
!
programme Loopback19
ip come 19.19.19.19 255.0.0.0
R1(config)#router ospf 1
R1(config-router)#redistribute adjoining subnets
These quaternary routes are seen on the downstream router R2 as External Type-2, the choice for routes redistributed into OSPF.
R2#show ip line ospf
O E2 17.0.0.0/8 [110/20 via 172.12.123.1, 00:00:07, Serial0
O E2 16.0.0.0/8 [110/20 via 172.12.123.1, 00:00:07, Serial0
O E2 19.0.0.0/8 [110/20 via 172.12.123.1, 00:00:07, Serial0
O E2 18.0.0.0/8 [110/20 via 172.12.123.1, 00:00:07, Serial0
You crapper belike do this account in your head, but do so before continuing with the lab. : )
R1(config)#router ospf 1
R1(config-router)#summary-address 16.0.0.0 252.0.0.0
Look at the disagreement in R2's OSPF table.
R2#show ip line ospf
O E2 16.0.0.0/6 [110/20 via 172.12.123.1, 00:00:05, Serial0
The outside routes hit been successfully summarized, and quaternary routes hit been summarized into digit azygos route. Note that the unofficial line is ease scarred as an E2 route.
There's an engrossing lateral gist from the account inform on R1:
R1#show ip line ospf
O 16.0.0.0/6 is a summary, 00:01:51, Null0
When you configure unofficial routes in OSPF, a line to null0 module be installed into the OSPF routing table. This helps to preclude routing loops. Any packets sure for the routes that hit been summarized module hit a individual correct in the routing table....
R1#show ip route
Gateway of terminal use is not set
C 17.0.0.0/8 is direct connected, Loopback17
C 16.0.0.0/8 is direct connected, Loopback16
C 19.0.0.0/8 is direct connected, Loopback19
C 18.0.0.0/8 is direct connected, Loopback18
O 16.0.0.0/6 is a summary, 00:01:51, Null0
.. and packets that do not correct digit of the summarized routes but do correct the unofficial line module be dropped.
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For a FREE double of his stylish e-books, How To Pass The CCNA and How To Pass The CCNP, meet meet the website! You crapper also intend FREE CCNA and CCNP communicating questions every day! Pass the CCNP communicating with The Bryant Advantage!
