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Summarizing routes is an important skill to learn to pass the BSCI Examination and acquire just one phase nearer to earning your CCNP. The actual binary conversions are only Element of the test, although! You’ve got to know how to correctly use the summary routes, Which differs from 1 protocol to the following. In the previous couple of CCNP / BSCI tutorials, we’ve checked out utilizing the “region range” and “summary-deal with” commands to carry out OSPF route summarization. Nowadays, we’ll Check out summarizing routes in EIGRP.
We’ll use the subsequent 4 loopback addresses in this example:
Loopback 16, sixteen.16.sixteen.sixteen /32
Loopback 17, 17.seventeen.seventeen.17 /32
Loopback 18, 18.eighteen.18.eighteen /32
Loopback 19. 19.19.19.19 /32
On R1, we’ll spot these 4 addresses into EIGRP AS a hundred.
R1(config-if)#router eigrp one hundred
R1(config-router)#network sixteen.16.sixteen.sixteen 0.0.0.0
R1(config-router)#community 17.17.17.17 0.0.0.0
R1(config-router)#community 18.18.eighteen.eighteen 0.0.0.0
R1(config-router)#network 19.19.19.19 0.0.0.0
R3 is undoubtedly an EIGRP neighbor of R1, Which router’s EIGRP routing table now appears like this:
R3#demonstrate ip route eigrp
seventeen.0.0.0/32 is subnetted, one subnets
D seventeen.seventeen.17.seventeen [90/2297856] by way of 172.12.123.one, 00:00:29, Serial0
16.0.0.0/32 is subnetted, 1 subnets
D 16.sixteen.sixteen.sixteen [ninety/2297856] by using 172.twelve.123.one, 00:00:36, Serial0
19.0.0.0/32 is subnetted, 1 subnets
D 19.19.19.19 [90/2297856] through 172.twelve.123.one, 00:00:08, Serial0
18.0.0.0/32 is subnetted, 1 subnets
D 18.eighteen.18.eighteen [90/2297856] through 172.12.123.1, 00:00:22, Serial0
To execute handbook route summarization, create out the network addresses in binary after which you can identify The purpose at which the addresses now not Have a very little bit in popular. For these 4 addresses, it will be enough to write down out the main octet in binary:
1600010000
1700010001
1800010010
1900010011
Performing from still left to appropriate, the typical bits are the primary six bits – 000100xx. In decimal, this price is sixteen. The summary mask has to be decided also, and that benefit is derived from putting a “one” during the mask for each typical bit. With the main six bits all established to at least one – 11111100 – the ensuing mask is 252.0.0.0. The total summary deal with is 16.0.0.0 252.0.0.0.
In EIGRP, the summary address is definitely configured on an interface, not beneath the routing procedure.
R1(config)#interface serial0
R1(config-if)#ip summary-handle eigrp one hundred 16.0.0.0 252.0.0.0
02:39:fifty: %Twin-five-NBRCHANGE: IP-EIGRP a hundred: Neighbor
172.twelve.123.3 (Serial0) is down: summary configured
172.12.123.two (Serial0) is down: summary configured
02:forty:16: %Twin-5-NBRCHANGE: IP-EIGRP a hundred: Neighbor
172.12.123.2 (Serial0) is up : new adjacency
02:forty:17: %Twin-five-NBRCHANGE: IP-EIGRP one hundred: Neighbor
172.twelve.123.3 (Serial0) is up: new adjacency
There’s a direct aspect influence here that most textbooks go away out. Your EIGRP adjacencies will come down after you configure this summary, but they must come back up rapidly. The crucial element word There is certainly “must”. If you configure EIGRP summary addresses with a generation network, you may want to do that during non-peak hrs. The timestamps on the above mentioned commands indicate which the adjacencies have been down for about 27 seconds over the NBMA community. That’s about thirty minutes in stop-user time. 😉
Check R3’s EIGRP routing desk.
D 16.0.0.0/six [ninety/2297856] by means of 172.12.123.1, 00:01:46, Serial0
The four summarized routes are now not within the routing https://socialhattori.com/ desk, they usually have already been changed with the summary route revealed at The underside of the routing table. Observe the mask is /five, that is prefix notation for 248.0.0.0.
Realizing how and why to summarize routes is often a valuable talent, regardless of the protocol in use. But prior to deciding to go ahead and take BSCI Examination with your technique to the CCNP, ensure you learn how to conduct summarization with all the Main protocols!