eigrp variance

[Pikachu]

I personally think the answer is 2 paths... ADEH being the best path... AFEH being the alternate path.

You said 4 paths... but this is wrong because the variance rule states that that the alternate paths must be LESS THAN  (variance X local best metric)  The other 2 paths are EQUAL TO 60, which is the variance of 2 multiplied by the local best metric 30.

"The metric of the entire path (the FD of the alternative route) must be lower than the
variance multiplied by the local best metric (the current FD). In other words, the met-
ric for the entire alternate path must be within the variance." -CiscoPress book

Do you agree?

I disagree. According to Cisco, the alternate paths' feasible distance must be less than or equal to the (feasible distance * variance) value of the lowest FD path to be considered for load balancing. However, in order for a route to be considered for load balancing, it must also be a feasible successor. Therefore even though there are 4 paths with feasible distances that would qualify them as load balancing candidates when multiplied by the variance value, only 3 of them have advertised distances that qualify them as feasible successors, so those are the only paths that will be used.


I know this thread is old, but this should clear up a few things for those who may stumble across it in the future.