™
Summarizing routes is a significant talent to learn to move the BSCI Examination and acquire just one move closer to earning your CCNP. The particular binary conversions are only A part of the take a https://socialhattori.com/ look at, even though! You’ve acquired to know how to correctly utilize the summary routes, and that differs from one particular protocol to another. In the last few CCNP / BSCI tutorials, we’ve looked at using the “spot vary” and “summary-deal with” instructions to conduct OSPF route summarization. Currently, we’ll Consider summarizing routes in EIGRP.
We’ll use the next 4 loopback addresses in this instance:
Loopback 16, sixteen.sixteen.16.16 /32
Loopback 17, 17.17.17.seventeen /32
Loopback eighteen, eighteen.18.eighteen.18 /32
Loopback 19. 19.19.19.19 /32
On R1, we’ll spot these 4 addresses into EIGRP AS one hundred.
R1(config-if)#router eigrp one hundred
R1(config-router)#community 16.16.16.16 0.0.0.0
R1(config-router)#community seventeen.17.17.seventeen 0.0.0.0
R1(config-router)#network eighteen.18.eighteen.eighteen 0.0.0.0
R1(config-router)#network 19.19.19.19 0.0.0.0
R3 is surely an EIGRP neighbor of R1, Which router’s EIGRP routing table now appears like this:
R3#exhibit ip route eigrp
17.0.0.0/32 is subnetted, one subnets
D 17.seventeen.seventeen.seventeen [ninety/2297856] through 172.twelve.123.1, 00:00:29, Serial0
sixteen.0.0.0/32 is subnetted, 1 subnets
D sixteen.sixteen.16.sixteen [90/2297856] via 172.twelve.123.1, 00:00:36, Serial0
19.0.0.0/32 is subnetted, 1 subnets
D 19.19.19.19 [ninety/2297856] by way of 172.twelve.123.1, 00:00:08, Serial0
18.0.0.0/32 is subnetted, 1 subnets
D 18.18.eighteen.eighteen [ninety/2297856] by means of 172.twelve.123.one, 00:00:22, Serial0
To complete manual route summarization, generate out the community addresses in binary and afterwards determine The purpose at which the addresses now not Possess a bit in common. For these 4 addresses, It will probably be ample to jot down out the main octet in binary:
1600010000
1700010001
1800010010
1900010011
Doing work from still left to right, the widespread bits are the initial 6 bits – 000100xx. In decimal, this worth is 16. The summary mask has to be identified too, and that benefit is derived from Placing a “1” from the mask for each common little bit. With the primary 6 bits all set to at least one – 11111100 – the resulting mask is 252.0.0.0. The complete summary address is sixteen.0.0.0 252.0.0.0.
In EIGRP, the summary tackle is actually configured on an interface, not underneath the routing process.
R1(config)#interface serial0
R1(config-if)#ip summary-tackle eigrp a hundred sixteen.0.0.0 252.0.0.0
02:39:50: %DUAL-five-NBRCHANGE: IP-EIGRP 100: Neighbor
172.12.123.3 (Serial0) is down: summary configured
172.twelve.123.2 (Serial0) is down: summary configured
02:40:sixteen: %Twin-5-NBRCHANGE: IP-EIGRP a hundred: Neighbor
172.twelve.123.2 (Serial0) is up : new adjacency
02:40:17: %Twin-five-NBRCHANGE: IP-EIGRP 100: Neighbor
172.12.123.3 (Serial0) is up: new adjacency
There’s a direct facet outcome right here that a lot of guides depart out. Your EIGRP adjacencies are likely to occur down When you configure this summary, but they need to come back up speedily. The real key word You can find “really should”. When you configure EIGRP summary addresses over a manufacturing network, you may want to make this happen throughout non-peak hours. The timestamps on the above commands point out the adjacencies had been down for approximately 27 seconds above the NBMA network. That’s about 30 minutes in conclude-person time. 😉
Verify R3’s EIGRP routing desk.
D 16.0.0.0/six [90/2297856] by means of 172.12.123.one, 00:01:46, Serial0
The 4 summarized routes are now not within the routing table, plus they have been replaced with the summary route shown at The underside in the routing desk. Detect the mask is /5, which can be prefix notation for 248.0.0.0.
Being aware of how and why to summarize routes is often a beneficial ability, whatever the protocol in use. But prior to deciding to go ahead and take BSCI Examination in your method to the CCNP, be sure to learn how to execute summarization with most of the core protocols!