7 Replies Latest reply: Aug 12, 2011 2:48 AM by Haroldo

# EIGRP K-values

Hi guys,

I need someone here to assure me that I'm not going crazy or that I got this totally wrong. Either way it'll help me. =)

"K values that are set to nonzero values are used to calculate the EIGRP metric, and K values that are set to 0 are not used..."

Q: Which of the following metrics are used by RouterB to calculate the EIGRP composite metric?

k1=0 k2=1 k3=0 k4=0 k5=0

The only "nonzero value" is K2/load so my question is... How can the exam environment request me to select bandwidth/k1 and load/k2 in order to be correct?

Can anyone expand on that please? Have I missed anything here? I know these are the non default values, but will bandwidth/k1 be used even though k1 is set to 0? I wouldn't think so.

Thanks,

• ###### 1. Re: EIGRP K-values

Hi,

K values are only multipliers.

So  in this case the EIGRP metric which formula is:

EIGRP Metric = 256*((K1*Bw) + (K2*Bw)/(256-Load) + K3*Delay)*(K5/(Reliability + K4)))

We are using the Bandwidth and the Load

Regards.

Alain.

• ###### 2. Re: EIGRP K-values

Alain,

Thanks for your reply. I think the keyword I was missing is "multipliers".

In that case, is it save for me to say that "Bandwidth is always used regardless of its K-value multiplier. However, the cannot be said about Delay." Is that correct?

Regards,

• ###### 3. Re: EIGRP K-values

Hi,

if k2 is also equal to zero then Bw won't be used. just throw the multipliers values into the composite metric formula.

Regards.

Alain.

• ###### 4. Re: EIGRP K-values

Alain,

I think that sums it up pretty well. Thanks for your help.

Regards,

• ###### 5. Re: EIGRP K-values

K1 -bandwidth and K3- delay are 1; others 0;

and by default, routers use K1 and K3 =1; other 0

you change that with command

metric weights tos K1 K2 K3 K4 K5

metric weights 0 1 0 1 0 0

• ###### 6. Re: EIGRP K-values

I wouldn't say "always" used.  Only if K1 or K2 is set to a non-zero number would bandwidth be used.

The other K values correspond to parts of the equation that do not at all involve bandwidth.

HTH,

Scott

• ###### 7. Re: EIGRP K-values

Thanks everyone. I think this is important to keep in mind as it can be easily overlooked. Well at least I did.

A quick summary based on what's been said here would be:

- K-values are multipliers

- Default is k1=1 k2=0 k3=1 k4=0 k5=0

- If K2/Load is set to a non-zero value, bandwidth is also used

Cheers,