Cisco CCNP / BSCI examination academic: route Summarization

making ready to skip the BSCI examination and earn your Cisco CCNP? route summarization is simply one of the many talents you'll need to grasp with a view to earn your CCNP. whether it is RIP model 2, OSPF, or EIGRP, the BSCI examination will call for that you could flawlessly configure direction summarization.

route summarization isn't simply critical for the BSCI examination. it is a precious skill to have in the actual global as well. calcolo percorso efficaciously summarizing routes can lead to smaller routing tables that are nonetheless capable of direction packets correctly - what i really like to name "concise and complete" routing tables.

the first ability you've got to have with a purpose to paintings with course summarization is binary math extra particularly, you have to be able to take more than one routes and come up with both a precis path and masks to put it up for sale to downstream routers. Given the networks 100.16.0.0 /16, 100.17.zero.zero /16, a hundred.18.0.zero /16, and 100.19.0.zero /16, could you speedy provide you with both the summary cope with and masks? All you need to do is wreck the four network numbers down into binary strings. We recognize the closing two octets will all convert to the binary string 00000000, so in this newsletter we will only illustrate the way to convert the first and 2d octet from decimal to binary.

100 16 = 01100100 00010000

one hundred 17 = 01100100 00010001

100 18 = 01100100 00010010

one hundred 19 = 01100100 00010011

To come up with the summary path, simply paintings from left to proper and draw a line wherein the 4 networks not have a bit in not unusual. For those four networks, that factor comes between the 14th and 15th bits. This leaves us with this string: 01100100 000100xx. All you need to do is convert that string back to decimal, which offers us one hundred for the first octet and 16 for the second one. (the two x values are bits on the proper aspect of the line, which are not utilized in calculating the precis route.) since we understand that zero is the cost for the final octets, the ensuing precis community range is one hundred.16.0.0.

however we are no longer finished! We now have to come up with the precis masks to put it up for sale at the side of the precis path. to reach on the summary direction, write out a masks in binary with a "1" for every bit to the left of the road we drew previously, and a "0" for each bit to the proper. That gives us the subsequent string:

11111111 11111100 00000000 00000000

changing that to dotted decimal, we arrive on the precis mask 255.252.zero.zero. an appropriate summary network and masks to put it on the market are a hundred.16.0.zero 252.zero.zero.zero.

For the BSCI examination, emphasis is placed on understanding how to promote it these precis routes in RIPv2, EIGRP, and OSPF. For RIP v2 and EIGRP, route summarization takes place at the interface degree it's now not configured underneath the protocol. on the interface that have to promote it the summary

route, use the command "ip summary-address". here are examples of how the above precis path would be configured on ethernet0 in both RIPv2 and EIGRP.

R1(config-if)#ip precis-deal with rip a hundred.sixteen.zero.0 255.252.zero.0

R1(config-if)#ip precis-cope with eigrp a hundred 100.16.zero.zero 255.252.zero.0

the main distinction between the two is that the EIGRP command have to specify the AS range - that is what the "100" is inside the center of the EIGRP command. seeing that RIPv2 does no longer use AS numbers, there's no additional price wished inside the configuration.

For OSPF, the instructions differ. if you're configuring inter-location course summarization, use the "region range" command. The number following "region" is the area containing the routes being summarized, now not the vicinity receiving the precis.

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