Quick EIGRP K Value metric question

[arvindchari]

Hi Guys

I was just a little confused about this.

While optimizing / manipulating EIGRP using the K Values what are the units in which we specify each of the metrics

E.g

metric = [K1*bandwidth + (K2*bandwidth)/(256 - load) + K3*delay] * [K5/(reliability + K4)]

so bandwidth is specified in bps

Load on a factor of 0 - 255 ditto for reliability but what is the factor for delay (secs / milli secs / micro secs)?

TIA

Arvind

[bhedlund · Accepted solution]

The metric is calculated with delay in microseconds.

The delay configured on an interface is in 10s of microseconds.

For example, if I have 'delay 8' configured on an interface I would use 80 in the metric calculation.

The 'show interface' and 'show ip eigrp topology' commands will show the delay in microseconds as it would be used in the metric calculation.

Please rate all helpful posts.

Brad

[arvindchari]

Thank you both for clearing that up for me. Just tend to get a little confused once in a while :)

Regards

Arvind

[b-ulrich]

Hi, delay is in microseconds. So if you are configuring on an interface 'delay 2000' you are really adding 20 microseconds of delay for the EIGRP metric. You should be able to see this take effect on your neighboring router in the ip routing table for that route. Take the number that you configure on the interface and divide it by 100.

http://www.cisco.com/en/US/customer/tech/tk365/technologies_white_paper09186a0080094cb7.shtml#metrics

[pkhatri · Accepted solution]

Hi Arvind,

I'm afraid Brad's explanation is not quite correct.

When using the formula to calculate the EIGRP metric, the delay has to be specified in 10s of microseconds, and not microseconds. Therefore, the delay value used when configuring the delay on an interface is exactly the same value that is used in the formula.

The following document explains this:

http://www.cisco.com/warp/public/103/eigrp-toc.html#eigrpmetrics

Hope that helps - pls rate the post if it does.

Paresh

[arvindchari]

Hi Paresh

Thanks for the link that cleared it all up quite nicely

Regards

Arvind

[bhedlund]

Paresh,

Thanks for catching my mistake. Next time I'll make sure my coffee is caffinated! :)

Regards,

Brad