[c-nsp] EIGRP metric and MTU

[Alex Semenyaka]

Collegues,

I've a little bit confused. A lot of sources (from textbooks to Cisco Tac Case
http://www.ciscotaccc.com/iprout/showcase?case=K10340813) say that EIGRP composite
metric takes into account bandwidth, delay, load, reliability and MTU. While all
is clear with the first four (well-known expression for EIGRP metric lists them
all), the role of MTU is absolutely unclear. I failed to find any source describing
the way MTU could influence the composite metric. Moreover, the document
http://www.cisco.com/en/US/customer/tech/tk365/technologies_white_paper09186a0080094cb7.shtm
(to which the mentioned TAC Case referred) says about MTU in the metric context
only

Minimum MTU is 1500 	This field is not used in metric calculations.

That differs from the description for load and reliability, those are "not used
BY DEFAULT" (so, could be used, if K2 and K5 will not be 0).

Could anyboudy make clear, does MTU and EIGRP metric really connected?
And if so, then how?


Sincerely, Alex.