Comments on: EIGRP metrics and path selection http://ccnprecertification.com/2004/05/05/eigrp-metrics-and-path-selection/ Study notes for the Cisco CCNP exam Tue, 10 Apr 2012 15:44:25 +0000 hourly 1 http://wordpress.org/?v=3.3.2 By: Joe Astorino http://ccnprecertification.com/2004/05/05/eigrp-metrics-and-path-selection/comment-page-1/#comment-92970 Joe Astorino Thu, 26 May 2011 01:39:42 +0000 http://ertw.com/ccnp/?p=22#comment-92970 The reason is because the formula actually changes depending on if K5 is 0 or not 0. If K5 = 0 that entire piece of the equation is not taken into consideration. If K5 != 0 the K5/Reliability + K4 piece is added in. The reason is because the formula actually changes depending on if K5 is 0 or not 0. If K5 = 0 that entire piece of the equation is not taken into consideration. If K5 != 0 the K5/Reliability + K4 piece is added in.

]]> By: Rishi http://ccnprecertification.com/2004/05/05/eigrp-metrics-and-path-selection/comment-page-1/#comment-92179 Rishi Thu, 11 Nov 2010 20:58:26 +0000 http://ertw.com/ccnp/?p=22#comment-92179 I have same question as Chris said.it should be + in (K3*Delay)+(K5/(Reliability + K4))) not *.But everywhere the formula is written same. I have same question as Chris said.it should be + in (K3*Delay)+(K5/(Reliability + K4))) not *.But everywhere the formula is written same.

]]> By: chris http://ccnprecertification.com/2004/05/05/eigrp-metrics-and-path-selection/comment-page-1/#comment-92173 chris Tue, 09 Nov 2010 18:20:38 +0000 http://ertw.com/ccnp/?p=22#comment-92173 Can someone explain to me why the classic EIGRP metric formula is correct when K5=0 will result in the mertic=0? EIGRP Metric = 256*((K1*Bw) + (K2*Bw)/(256-Load) + (K3*Delay)*(K5/(Reliability + K4))) It would seem there should be a '+' between the K3 and K5 components in the formula like this ... EIGRP Metric = 256*((K1*Bw) + (K2*Bw)/(256-Load) + (K3*Delay)+(K5/(Reliability + K4))) Can someone explain to me why the classic EIGRP metric formula is correct when K5=0 will result in the mertic=0?
EIGRP Metric = 256*((K1*Bw) + (K2*Bw)/(256-Load) + (K3*Delay)*(K5/(Reliability + K4)))

It would seem there should be a ‘+’ between the K3 and K5 components in the formula like this …
EIGRP Metric = 256*((K1*Bw) + (K2*Bw)/(256-Load) + (K3*Delay)+(K5/(Reliability + K4)))

]]> By: esme http://ccnprecertification.com/2004/05/05/eigrp-metrics-and-path-selection/comment-page-1/#comment-92131 esme Fri, 24 Sep 2010 01:08:27 +0000 http://ertw.com/ccnp/?p=22#comment-92131 hola te dejo dos formulas que ambas sirven para calcular la metrica de eigrp. metric=(k1*BW+K3*DELAY) 2da. formula.... metric=(K1*BW+(K2*BW)/(256-LOAD)+(K3*DELAY)*(K5/(CONFILIDAD+K4)) hola te dejo dos formulas que ambas sirven para calcular la metrica de eigrp.

metric=(k1*BW+K3*DELAY)

2da. formula…. metric=(K1*BW+(K2*BW)/(256-LOAD)+(K3*DELAY)*(K5/(CONFILIDAD+K4))

]]> By: Mehboob http://ccnprecertification.com/2004/05/05/eigrp-metrics-and-path-selection/comment-page-1/#comment-92043 Mehboob Wed, 04 Aug 2010 06:13:20 +0000 http://ertw.com/ccnp/?p=22#comment-92043 EIGRP is used for Loadblancing upto 6paths EIGRP is used for Loadblancing upto 6paths

]]> By: Mehboob http://ccnprecertification.com/2004/05/05/eigrp-metrics-and-path-selection/comment-page-1/#comment-92042 Mehboob Wed, 04 Aug 2010 06:09:59 +0000 http://ertw.com/ccnp/?p=22#comment-92042 Bandwidth and Delay is metric of EIGRP Its comfirmed 100% Bandwidth and Delay is metric of EIGRP
Its comfirmed 100%

]]> By: Kishore http://ccnprecertification.com/2004/05/05/eigrp-metrics-and-path-selection/comment-page-1/#comment-92014 Kishore Wed, 07 Jul 2010 07:00:15 +0000 http://ertw.com/ccnp/?p=22#comment-92014 MTU doesnt affect path selection but I guess its just been included so that maybe in future they might put that in as a consideration as well. just like ospf does check MTU when exchanging DD packets, maybe in future Eigrp might use this as well. Who knows;-) MTU doesnt affect path selection but I guess its just been included so that maybe in future they might put that in as a consideration as well.

just like ospf does check MTU when exchanging DD packets, maybe in future Eigrp might use this as well. Who knows;-)

]]> By: sean http://ccnprecertification.com/2004/05/05/eigrp-metrics-and-path-selection/comment-page-1/#comment-92011 sean Sun, 04 Jul 2010 01:46:39 +0000 http://ertw.com/ccnp/?p=22#comment-92011 You guys are right, it's tracked but not used in the calculation. Why the heck does every book I see, from a CCNA text up to Doyle, feel the need to include it when talking about metrics when it's really not used? You guys are right, it’s tracked but not used in the calculation.

Why the heck does every book I see, from a CCNA text up to Doyle, feel the need to include it when talking about metrics when it’s really not used?

]]> By: Tom http://ccnprecertification.com/2004/05/05/eigrp-metrics-and-path-selection/comment-page-1/#comment-92008 Tom Fri, 02 Jul 2010 09:19:54 +0000 http://ertw.com/ccnp/?p=22#comment-92008 Although MTU and hop count are mentioned in <b>show ip eigrp topology</b>, they aren't in the formula for calculating the metric, being <i>metric = [K1 * bandwidth + (K2 * bandwidth) / (256 - load) + K3 * delay] * [K5 / (reliability + K4)]</i> so they really aren't metrics, since there is no way to include them in the metric calculation. Although MTU and hop count are mentioned in show ip eigrp topology, they aren’t in the formula for calculating the metric, being metric = [K1 * bandwidth + (K2 * bandwidth) / (256 - load) + K3 * delay] * [K5 / (reliability + K4)] so they really aren’t metrics, since there is no way to include them in the metric calculation.

]]> By: sean http://ccnprecertification.com/2004/05/05/eigrp-metrics-and-path-selection/comment-page-1/#comment-91913 sean Thu, 18 Jun 2009 18:23:59 +0000 http://ertw.com/ccnp/?p=22#comment-91913 Hi, Have a look at http://www.cisco.com/en/US/tech/tk365/technologies_white_paper09186a0080094cb7.shtml Minimum MTU along the path is an EIGRP metric, with the default K values it's not calculated though. It's there, look at the <em>show ip eigrp top</em> output. Sean Hi,

Have a look at http://www.cisco.com/en/US/tech/tk365/technologies_white_paper09186a0080094cb7.shtml

Minimum MTU along the path is an EIGRP metric, with the default K values it’s not calculated though. It’s there, look at the show ip eigrp top output.

Sean

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