CCNP / BSCI Exam Tutorial: Route Summarization As well as the OSPF Null Interface
CCNP Examination achievement, notably http://edition.cnn.com/search/?text=토토사이트 over the BSCI Test, needs you have an understanding of the details of route summarization. This ability not just calls for that you've got a ease and comfort level with binary conversions, but You need to know the way and wherever to use route summarization with Each individual specific protocol.
You also have to learn the “Negative effects” of route summarization. With OSPF, there'll really be an additional interface created at The purpose of summarization, and this catches a great deal of CCNP candidates unexpectedly. Let’s take a look at the null0 interface And just how it pertains to OSPF summarization.
On R1, the next networks are redistributed into OSPF, after which you can summarized.
interface Loopback16
ip deal with sixteen.16.sixteen.16 255.0.0.0
interface Loopback17
ip tackle 17.seventeen.17.17 255.0.0.0
interface Loopback18
ip deal with eighteen.eighteen.18.18 255.0.0.0
interface Loopback19
ip address 19.19.19.19 255.0.0.0
R1(config)#router ospf one
R1(config-router)#redistribute connected subnets
R1(config-router)#summary-deal with sixteen.0.0.0 252.0.0.0
The summary handle seems on R2, a downstream router.
R2#show ip route ospf
O E2 16.0.0.0/6 [a hundred and ten/20] by using 172.12.123.1, 00:00:05, Serial0
Permit’s go back to R1 and have a look at its OSPF desk.
R1#demonstrate ip route ospf
O 16.0.0.0/six is usually a summary, 00:01:51, Null0
Wherever did the null0 interface come from, and why can it be there? Packets sent to your null interface are dropped, and In cases like this, that’s a good matter.
Once you configure summary routes 토토사이트 in OSPF, a route to null0 are going to be set up to the OSPF routing table. This can help to prevent routing loops. Any packets destined to the routes which have been summarized will likely have an extended match inside the routing table, as demonstrated under…
C seventeen.0.0.0/8 is instantly connected, Loopback17
C sixteen.0.0.0/eight is specifically linked, Loopback16
C 19.0.0.0/eight is instantly linked, Loopback19
C eighteen.0.0.0/eight is right linked, Loopback18
O sixteen.0.0.0/six is a summary, 00:01:fifty one, Null0
.. and packets that don't match one of several summarized routes but do match the summary route will be dropped.
Stopping routing loops when performing route redistribution and summarization is significant. OSPF presents us a little bit assist in that regard in this situation, and as you analyze a lot more intricate redistribution situations with your approach to the CCNP and CCIE, you’ll recognize that we’ll take all the help we will get!