While you're preparing to go the CCNA examination and earn this coveted Cisco certification, you have to be totally ready for the many kinds of binary and subnetting questions Cisco could throw at you. You also should be acquainted with the totally different manners in which a subnet masks might be expressed, as within the following: 255.255.255.zero /24 Imagine it or not, those two values are exactly the same. The first mask is written out within the extra acquainted dotted decimal format, and you understand by looking at those first three octets that each bit is about to "1", since the maximum worth of such an octet is 255. The second value represents the very same mask, only this worth is expressed in prefix notation. This particular value would be pronounced "slash twenty-four", and the 24 represents the variety of consecutive ones which might be set within the subnet mask. Those of us who hate to sort numbers are notably appreciative of this, because it means you'll have to kind so much much less numbers to characterize a subnet mask. In addition, it is loads easier to debate masks in prefix notation than dotted decimal. ("I thought of using a -fifty-5 -fifty-5 two-fifty-five zero masks ,however then decided to make use of a -fifty-5 two-fifty-five two-fifty-five one-twenty-eight mask...") Make certain you're comfortable with prefix notation earlier than taking your CCNA exam. As with Cisco documentation, you'll almost definitely see masks expressed in both dotted decimal and prefix notation, and you've got to be prepared to make use of the both as nicely! RIP isn't precisely essentially the most advanced routing protocol on the CCNA exam, but that makes it easy to miss a number of the vital particulars you have to consider to be able to move the exam! That can assist you overview for the exam, listed below are only a few of these details! RIP's default conduct is to send version 1 updates, however to accept each model 1 and 2 routing updates. R2(config)router rip R2(config-router)net 172.16.0.zero R2(config-router)^Z R2show ip protocols Routing Protocol is "rip" Sending updates every 30 seconds, next due in 6 seconds Invalid after one hundred eighty seconds, hold down 180, flushed after 240 Outgoing update filter checklist for all interfaces is Incoming replace filter listing for all interfaces is Redistributing: rip Default model management: send model 1, receive any model Interface Send Recv Key-chain Serial0 1 1 2 By default, RIP v2 autosummarizes routing updates despatched across classful network boundaries. To disable this behavior, run no auto-abstract beneath the RIP process. R1conf t R1(config)router rip R1(config-router)model 2 R1(config-router)no auto-summary You don't specify a subnet masks or wildcard masks when configuring RIP - simply the classful network, even in the event you're operating RIP v2. R1conf t Enter configuration instructions, one per line. Finish with CNTL/Z. R1(config)router rip R1(config-router)version 2 R1(config-router)no auto-summary R1(config-router)community 172.10.0.zero ? Debug ip rip displays the routing updates and metrics because the commercials are sent and requested. To see this in motion without waiting for the subsequent often scheduled update, run clear ip route *. R1debug ip rip RIP protocol debugging is on R1clear ip route * 01:16:54: RIP: sending v1 update to 255.255.255.255 through Loopback1 (1.1.1.1) 01:16:54: community 2.0.0.0, metric 2 01:16:54: community 3.0.0.0, metric 2 01:sixteen:fifty four: community 172.16.0.0, metric 1 01:sixteen:fifty four: network 10.0.0.zero, metric 2 01:sixteen:54: RIP: sending v1 update to 255.255.255.255 via Serial0 (172.16.123.1) 01:16:fifty four: subnet 172.16.123.zero, metric 1 01:16:fifty four: network 1.0.0.zero, metric 1 01:16:54: community 2.0.0.0, metric 2 01:16:54: community 3.0.0.zero, metric 2 01:16:fifty four: community 10.0.0.0, metric 2 To see solely the routes discovered by a routing protocol, run present ip route adopted by the title of the protocol: R1show ip route rip R 2.0.0.zero/8 [120/1] by way of 172.16.123.2, 00:00:26, Serial0 R 3.0.0.0/eight [120/1] via 172.16.13.2, 00:00:09, Serial1 [120/1] through 172.16.123.three, 00:00:09, Serial0 R 10.0.0.0/8 [120/1] via 172.16.13.2, 00:00:09, Serial1 [120/1] through 172.16.123.three, 00:00:09, Serial0 [120/1] through 172.16.123.2, 00:00:26, Serial0 And remember - to show off all presently operating debugs, run undebug all. R1undebug all All attainable debugging has been turned off Don't overlook RIP and IGRP relating to the CCNA exam. OSPF and EIGRP are more complicated to configure, however it is advisable perceive how distance vector protocols work in order to cross the CCNA! To pass the CCNA examination, you have to know how you can work with IGRP and EIGRP unequal-cost load balancing. It's possible you'll not see a lot IGRP in manufacturing networks anymore, but you may see a number of EIGRP, and a part of fantastic-tuning your EIGRP community is making sure that each one paths are in use whereas allowing for various bandwidth rates. Using the variance command is the straightforward part - it is getting the metric that is the arduous half with IGRP. With EIGRP, you simply look in the topology desk and that's it. With IGRP, you've got to run a debug to get the proper metric. The variance command is a multiplier when the worth provided with the variance command is multiplied by the bottom-cost metric, it must exceed the higher-value metric in order for the upper-cost route to be added. If that sounds sophisticated, it's not. It's a kind of issues that sounds tough, however isn't. Belief me! On this instance, R1 has paths to 172.23.0.zero, but is presently using solely one. By trying within the IP routing desk, we've seen that the lowest-cost metric for community 172.23.0.zero on R1 is 8576. This path goes by means of the 172.12.123.0 network. There's one other legitimate path that uses the 172.12.13.zero community, however isn't at the moment in use. I 172.23.0.0/16 [100/8576] through 172.12.123.2, 00:00:53, Serial0 IGRP doesn't have a "show" command that shows all valid routes to a vacation spot, as does EIGRP. The command debug ip igrp transactions will present the present metric of the routes utilizing the 512 KBPS route. R1debug ip igrp transactions IGRP protocol debugging is on 19:17:fifty one: IGRP: broadcasting request on Loopback0 19:17:51: IGRP: broadcasting request on Serial0 19:17:fifty one: IGRP: broadcasting request on Serial1 19:17:51: IGRP: received update from 172.12.13.3 on Serial1 19:17:fifty one: subnet 172.12.13.zero, metric 23531 (neighbor 21531) 19:17:51: subnet 172.12.123.0, metric 23531 (neighbor 8476) 19:17:51: community 1.0.0.zero, metric 24031 (neighbor 8976) 19:17:51: network 2.0.0.zero, metric 22131 (neighbor 1600) 19:17:51: network 3.0.0.0, metric 22031 (neighbor 501) 19:17:51: community 172.23.0.0, metric 21631 (neighbor 1100) R1(config)router igrp 1 R1(config-router)variance 3 R1show ip route 172.23.0.0 Routing entry for 172.23.0.0/sixteen Identified through "igrp 1", distance one hundred, metric 8576 Redistributing by way of igrp 1 Marketed by igrp 1 (self originated) Final update from 172.12.123.2 on Serial0, 00:00:01 ago Routing Descriptor Blocks: * 172.12.13.three, from 172.12.13.3, 00:00:20 in the past, by way of Serial1 Route metric is 21631, traffic share depend is 1 Whole delay is 21000 microseconds, minimum
Article Source: http://www.articlecontentprovider.com/articlesubmit
To go the CCNA examination, you must know the best way to use prefix notation. Find out how from Chris Bryant, CCIE 12933.
You may learn more in my site , i'm happy that you simply learn my article, thnak you , you can visit right here bart simpson pictures
Please Rate this Article
5 out of 5 4 out of 5 3 out of 5 2 out of 5 1 out of 5
