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.
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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<http://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<http://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
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