Yes Steve , you are right , the result is same. it is alwyas werid becuase most of COD/VOD/Book give this formula and claim it will match but every now then when ever I study this topic I got a differnce in calculation.
Look like we may miss something when we calculate metic with given formula. On Tue, Dec 7, 2010 at 11:31 PM, Di Bias, Steve <[email protected]>wrote: > Tyson, I used this formula and came up with the same results > > > > *Delay = sum of all delays in the path in 10’s of microseconds > (multiplied) by 256* > > *Bandwidth = [10 o the 7th power / (least bandwidth in kilobits per sec)] > * 256* > > * * > > *Metric = [k1 * bandwidth + (k2 * bandwidth)/(256 - load) + k3 * delay]* > > * * > > *Or in the case of only K1 and K3* > > > > *Metric = (slowest link bandwidth) + (sum of all delays)* > > > > *10000000 / 1544 = 6476.6839378238341968911917098446 x 256 = 1658031* > > *2500 x 256 = 640000* > > *1658031 + 640000 = 2298031* > > > > Steve > > > ------------------------------ > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *Tyson Scott > *Sent:* Tuesday, December 07, 2010 9:48 AM > *To:* 'amit chopra'; [email protected]; > [email protected]; 'Marko Milivojevic' > *Subject:* Re: [OSL | CCIE_RS] EIGRP unequal cost load > > > > Did you go thru this blog. > > > > http://blog.ipexpert.com/2010/05/03/eigrp-unequal-cost-load-balancing/ > > > > Your numbers are a little off > > > > It should be 256 & 10^10 > > > > Regards, > > > > Tyson Scott - CCIE #13513 R&S, Security, and SP > > Managing Partner / Sr. Instructor - IPexpert, Inc. > > Mailto: [email protected] > > Telephone: +1.810.326.1444, ext. 208 > > Live Assistance, Please visit: www.ipexpert.com/chat > > eFax: +1.810.454.0130 > > > > IPexpert is a premier provider of Self-Study Workbooks, Video on Demand, > Audio Tools, Online Hardware Rental and Classroom Training for the Cisco > CCIE (R&S, Voice, Security & Service Provider) certification(s) with > training locations throughout the United States, Europe, South Asia and > Australia. Be sure to visit our online communities at > www.ipexpert.com/communities and our public website at www.ipexpert.com > > > > *From:* amit chopra [mailto:[email protected]] > *Sent:* Tuesday, December 07, 2010 12:22 PM > *To:* [email protected]; [email protected]; > Marko Milivojevic; Tyson Scott > *Subject:* EIGRP unequal cost load > > > > Always an issue when it is come to calculation :) I watched VOD for EIGRP > unequal cost load balacing and try to calculate FD by following formula > > > > > > Rack1R5#show ip eigrp topology 4.0.0.0 > IP-EIGRP (AS 100): Topology entry for 4.0.0.0/8 > State is Passive, Query origin flag is 1, 2 Successor(s), FD is 2297856 > Routing Descriptor Blocks: > 155.1.0.4 (Serial1/0.1), from 155.1.0.4, Send flag is 0x0 > Composite metric is (2297856/128256), Route is Internal > Vector metric: > Minimum bandwidth is 1544 Kbit > Total delay is 25000 microseconds > Reliability is 255/255 > Load is 1/255 > Minimum MTU is 1500 > Hop count is 1 > > To know how metric calculated on above output , I used following formula: > > a) 2.56 x 10^12 / BW (in bps) = 2.56 x 1000000000000 / 1544000 = > 1658031.0880829015544041450777202 = 1658031 > > b) Delay : 2500 x 256 = 640000 > > Metric = a + b = 1658031 + 640000 = *2298031* > > Now as per output , The metric for 4.0.0.0 is 2297856 and if I subtract > both metric it will come up 175 , not sure why it is not match exactly. > > The 4.0.0.0 prefix is advertise by router 4 : > > Rack1R4# sh ip eigrp topology 4.0.0.0 > IP-EIGRP (AS 100): Topology entry for 4.0.0.0/8 > State is Passive, Query origin flag is 1, 1 Successor(s), FD is 128256 > Routing Descriptor Blocks: > 0.0.0.0 (Loopback4), from Connected, Send flag is 0x0 > Composite metric is (128256/0), Route is Internal > Vector metric: > Minimum bandwidth is 10000000 Kbit > Total delay is 5000 microseconds > Reliability is 255/255 > Load is 1/255 > Minimum MTU is 1514 > Hop count is 0 > Rack1R4# > > Please guys help > > > > UHS Confidentiality Notice: This e-mail message, including any attachments, > is for the sole use of the intended recipient(s) and may contain > confidential and privileged information. Any unauthorized review, use, > disclosure or distribution of this information is prohibited, and may be > punishable by law. If this was sent to you in error, please notify the > sender by reply e-mail and destroy all copies of the original message.
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