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ICND2 – EtherChannel Questions

October 29th, 2017 in ICND2 200-105 Go to comments

Question 1

Explanation

The way EtherChannel load balancing works is that the switch assigns a hash result from 0-7 based on the configured hash method ( load balancing algorithm ) for the type of traffic. This hash result is commonly called as Result Bundle Hash (RBH).

Now we need to convert Load value from Hexadecimal to Binary numbers. Therefore:
+ Gi1/1: 36 (Hex) = ‭00110110‬ (Bin) -> Bits 3, 4, 6, 7 are chosen
+ Gi1/2: 84 (Hex) = ‭10000100‬ (Bin) -> Bits 1, 6 are chosen
+ Gi1/3: 16 (Hex) = ‭00010110‬ (Bin) -> Bits 4, 6, 7 are chosen

Therefore if the RBH is 3, it will choose Gi1/1. If RBH is 4, it will choose Gi1/1 and Gi1/3 interfaces. If RBH is 6 it will choose all three above interfaces. And the bit sharing ratio is 3:3:2 (from “No of bits” column) hence two links has higher probability of getting utilized as compared to the third link.

Question 2

Explanation

In PAgP we only have two modes: auto and desirable.

Question 3

Explanation

The way EtherChannel load balancing works is that the switch assigns a hash result from 0-7 based on the configured hash method ( load balancing algorithm ) for the type of traffic. This hash result is commonly called as Result Bundle Hash (RBH).

Now we need to convert Load value from Hexadecimal to Binary numbers. Therefore:
+ Gi1/1: 36 (Hex) = ‭00110110‬ (Bin) -> Bits 3, 4, 6, 7 are chosen
+ Gi1/2: 84 (Hex) = ‭10000100‬ (Bin) -> Bits 1, 6 are chosen
+ Gi1/3: 16 (Hex) = ‭00010110‬ (Bin) -> Bits 4, 6, 7 are chosen

Therefore if the RBH is 3, it will choose Gi1/1. If RBH is 4, it will choose Gi1/1 and Gi1/3 interfaces. If RBH is 6 it will choose all three above interfaces. And the bit sharing ratio is 3:3:2 (from “No of bits” column) hence two links has higher probability of getting utilized as compared to the third link.

Question 4

Explanation

In PAgP we only have two modes: auto and desirable.

Comments (2) Comments
  1. zahir
    August 10th, 2017

    need more questions please.

  2. Kenno
    November 10th, 2017

    Thanks Archie, that’s bloody wonderful. I’ll never forget you or your upload 🙂