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EIGRP load and reliability

How EIGRP calculates load and reliability.

how can i reset the values to make my high bandwidth path to be best route again.

is this related to 5 min input and output calculation.

In EIGRP RTS/SRTT values are propritory and on this load and reliability is depend i think

please help

thanks in advance

1 ACCEPTED SOLUTION

Accepted Solutions
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Re: EIGRP load and reliability

"How EIGRP calculates load and reliability?"

EIGRP doesn't calculate load and reliability, it takes them from the interface counters, as calculated by interface code. Generally, load is based on the amount of bandwidth available (based on the configured bandwidth), converted to a number between 0 and 255 (so 255 is 100% load, while 0 is 0% load). Reliability is generally based on packets dropped, or errors, depending on the interface type, and is also adjusted to be between 0 and 255.

Note that while these numbers are dynamic, EIGRP doesn't read them from the interface dynamically. In other words, when the EIGRP neighbor relationship first comes up, the reliability and load are read from the interface, and after that, they remain constant, from EIGRP's perspective, until the neighbor relationship on the interface is cleared.

HTH.

:-)

Russ.W

3 REPLIES

Re: EIGRP load and reliability

Hi Kamlesh,

By default, EIGRP doesnot take Load and reliability into consideration. As K1=1,K2=0,K3=1,K4=0,K5=0.Its takes bandwidth and delay into account for calculating the metric. If you want EIGRP to take all the 5 parameters into account, then either it can be configured to use default values under the interfaces or the vlaues that you want.

HTH,

-amit singh

Gold

Re: EIGRP load and reliability

"How EIGRP calculates load and reliability?"

EIGRP doesn't calculate load and reliability, it takes them from the interface counters, as calculated by interface code. Generally, load is based on the amount of bandwidth available (based on the configured bandwidth), converted to a number between 0 and 255 (so 255 is 100% load, while 0 is 0% load). Reliability is generally based on packets dropped, or errors, depending on the interface type, and is also adjusted to be between 0 and 255.

Note that while these numbers are dynamic, EIGRP doesn't read them from the interface dynamically. In other words, when the EIGRP neighbor relationship first comes up, the reliability and load are read from the interface, and after that, they remain constant, from EIGRP's perspective, until the neighbor relationship on the interface is cleared.

HTH.

:-)

Russ.W

Hall of Fame Super Silver

Re: EIGRP load and reliability

Russ makes a good point that the load and reliability are read when the neighbor relationship is formed and do not change dynamically. I believe that another aspect to point out is that (at least by default) while EIGRP gets the values and includes the values in advertisements, EIGRP does not use these values in calculatint the route metric. Based on the default K values EIGRP uses the bandwidth and delay but not the reliability or load or MTU.

HTH

Rick

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