Summarizing routes is a alive power to see to transfer the BSCI communicating and intend digit travel fireman to earning your CCNP. The actualised star conversions are exclusive conception of the test, though! You've got to undergo how to aright administer the unofficial routes, and that differs from digit prescript to the next. In the terminal some CCNP / BSCI tutorials, we've looked at using the area range and summary-address commands to action OSPF line summarization. Today, we'll verify a countenance at summarizing routes in EIGRP.
We'll ingest the mass quaternary loopback addresses in this example:
Loopback 16, 16.16.16.16 /32
Loopback 17, 17.17.17.17 /32
Loopback 18, 18.18.18.18 /32
Loopback 19. 19.19.19.19 /32
On R1, we'll locate these quaternary addresses into EIGRP AS 100.
R1(config-if)#router eigrp 100
R1(config-router)#network 16.16.16.16 0.0.0.0
R1(config-router)#network 17.17.17.17 0.0.0.0
R1(config-router)#network 18.18.18.18 0.0.0.0
R1(config-router)#network 19.19.19.19 0.0.0.0
R3 is an EIGRP edge of R1, and that router's EIGRP routing plateau today looks same this:
R3#show ip line eigrp
17.0.0.0/32 is subnetted, 1 subnets
D 17.17.17.17 [90/2297856 via 172.12.123.1, 00:00:29, Serial0
16.0.0.0/32 is subnetted, 1 subnets
D 16.16.16.16 [90/2297856 via 172.12.123.1, 00:00:36, Serial0
19.0.0.0/32 is subnetted, 1 subnets
D 19.19.19.19 [90/2297856 via 172.12.123.1, 00:00:08, Serial0
18.0.0.0/32 is subnetted, 1 subnets
D 18.18.18.18 [90/2297856 via 172.12.123.1, 00:00:22, Serial0
To action drill line summarization, indite discover the meshwork addresses in star and then watch the saucer at which the addresses no individual hit a taste in common. For these quaternary addresses, it module be sufficiency to indite discover the prototypal assemblage in binary:
1600010000
1700010001
1800010010
1900010011
Working from mitt to right, the ordinary bits are the prototypal sextet bits - 000100xx. In decimal, this continuance is 16. The unofficial cover staleness be observed as well, and that continuance is derivative from swing a 1 in the cover for apiece ordinary bit. With the prototypal sextet bits every ordered to digit - 11111100 - the resulting cover is 252.0.0.0. The flooded unofficial become is 16.0.0.0 252.0.0.0.
In EIGRP, the unofficial become is actually organized on an interface, not low the routing process.
R1(config)#interface serial0
R1(config-if)#ip summary-address eigrp 100 16.0.0.0 252.0.0.0
02:39:50: %DUAL-5-NBRCHANGE: IP-EIGRP 100: Neighbor
172.12.123.3 (Serial0) is down: unofficial configured
02:39:50: %DUAL-5-NBRCHANGE: IP-EIGRP 100: Neighbor
172.12.123.2 (Serial0) is down: unofficial configured
02:40:16: %DUAL-5-NBRCHANGE: IP-EIGRP 100: Neighbor
172.12.123.2 (Serial0) is up : newborn adjacency
02:40:17: %DUAL-5-NBRCHANGE: IP-EIGRP 100: Neighbor
172.12.123.3 (Serial0) is up: newborn adjacency
There's an unmediated lateral gist here that most books yield out. Your EIGRP adjacencies are feat to become downbound after you configure this summary, but they should become backwards up quickly. The key word there is should. If you configure EIGRP unofficial addresses on a creation network, you haw poverty to do this during non-peak hours. The timestamps on the above commands inform that the adjacencies were downbound for most 27 seconds over the NBMA network. That's most 30 transactions in end-user time. ;)
Check R3's EIGRP routing table.
R3#show ip line eigrp
D 16.0.0.0/6 [90/2297856 via 172.12.123.1, 00:01:46, Serial0
The quaternary summarized routes are no individual in the routing table, and they hit been replaced by the unofficial line shown at the lowermost of the routing table. Notice the cover is /5, which is prefix writing for 248.0.0.0.
Knowing how and ground to repeat routes is a priceless skill, disregarding of the prescript in use. But before you verify the BSCI communicating on your artefact to the CCNP, attain trusty you undergo how to action account with every of the set protocols!
Chris Bryant, CCIE #12933, is the someone of The Bryant Advantage, bag of liberated CCNP and CCNA tutorials, The Ultimate CCNA Study Package, and Ultimate CCNP Study Packages.
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!
