What are the two default metrics used by EIGRP for route selection? (Choose two.)

What are the two default metrics used by EIGRP for route selection? (Choose two.)
A . Bandwidth
B . Delay
C . Reliability
D . Load
E . MTU

View Answer

Answer: A, B

Explanation:

EIGRP adds together weighted values of different network link characteristics in order to calculate a metric for evaluating path selection.

These characteristics include:

• Delay (measured in 10s of microseconds)

• Bandwidth (measured in kilobytes per second)

• Reliability (in numbers ranging from 1 to 255; 255 being the most reliable)

• Load (in numbers ranging from 1 to 255; 255 being saturated)

Various constants (K 1 through K 5) are able to be set by a user to produce varying routing behaviors.

However by default, only delay and bandwidth are used in the weighted formula to produce a single 32bit metric:

Note: Default K values are: K1 = K3 = 1 and K2 = K4 = K5 = 0

When K5 is equal to 0 then [K5/( K4 + reliability)] is defined to be 1

Use of the default constants effectively reduces the formula above to:

Reference: http://www.cisco.com/c/en/us/products/collateral/ios-nx-os-software/enhanced-interior-gateway-routing-protocol-eigrp/whitepaper_C11-720525.html