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EtherChannel Questions 3

September 12th, 2017 in SWITCH 300-115 Go to comments

Question 1

Explanation

From the outputs of the “show etherchannel summary” commands we learn that Switch1 is configuring EtherChannel with LACP while Switch2 is configuring with EtherChannel “on” mode -> the EtherChannel bundle does not go up.

Question 2

Question 3

Question 4

Question 5

Question 6

Question 7

Question 8

Question 9

Explanation

By default, when an LACP channel is configured, the LACP channel mode is passive.

Reference: http://www.cisco.com/c/en/us/support/docs/lan-switching/etherchannel/19642-126.html

Question 10

Explanation

From the output above, we see the “Protocol” field is empty (with a “-” sign). Therefore we can conclude it does not run any EtherChannel protocol (mode “on”). This EtherChannel is up with “(SU)” keywords (“S” means “Layer 2” and “U” means “up”) -> This is an Layer 2 EtherChannel mode “on”.

Comments
  1. mikeSWE
    July 19th, 2017

    q6. other dumps are giving different answers please confirm @Certprepare

  2. Ovione
    August 22nd, 2017

    Hello q6 which is it? C or D? Thanks

  3. Anonymous
    August 23rd, 2017

    Q6 : D. Destination MAC

  4. noob
    August 23rd, 2017

    On Q6 the answer is D. Destination MAC. You have only one bradcast domain.

  5. Anonymous
    September 10th, 2017

    Question 2
    There was an EtherChannel configured and one of the port was used as SPAN destination. What will be the result?
    A. the EtherChannel will not be operational because the port cannot be used as SPAN destination B. EtherChannel will discard the port used C. the EtherChannel will shutdown

    Answer A

    as oer https://www.cisco.com/c/en/us/support/docs/switches/catalyst-6500-series-switches/10570-41.html#anc63

    Can You Configure SPAN on an EtherChannel Port?

    An EtherChannel does not form if one of the ports in the bundle is a SPAN destination port. If you try to configure SPAN in this situation, the switch tells you:
    Channel port cannot be a Monitor Destination Port
    Failed to configure span feature
    You can use a port in an EtherChannel bundle as a SPAN source port.

  6. NJ
    October 15th, 2017

    Question 2
    I am confused with this.

    https://www.cisco.com/c/en/us/support/docs/switches/catalyst-6500-series-switches/10570-41.html

    Characteristics of Destination Port:
    A destination port can be a physical port that is assigned to an EtherChannel group, even if the EtherChannel group has been specified as a SPAN source. The port is removed from the group while it is configured as a SPAN destination port.

    So the answer is B?

  7. Al
    October 23rd, 2017

    Q 2
    The answer is B.
    Suppose that 5 ports from switch A (13-17) and 5 ports from switch B (13-17) are taking part in creating Po1. If I use port 14 on the switch 2 as the destination of Monitor session 5, then the outcome is as follows:
    Show ip int brief shows port 14 on the both switches as up down.
    Sh ether sum will show the port 14 on the switch B (the switch with SPAN set up) as (D) down, however, the other switch will show its own 14’s port as suspended.
    So I gather that the switch B will cast out its port 14, because it does not conform with the rules of Etherchannel. And as a result, port 14 on the other switch goes down. However, the rest of the Etherchannel (13,15,16,17) from both switches will continue setting up a healthy port-channel.

    Thanks

  8. Al
    October 23rd, 2017

    Apologies, switch B instead of switch 2 in the line 4.

  9. YMD
    November 7th, 2017

    Q6: This question misses information: which interface are you configuring, and/or what are the switch types. Destination mac/ip only works upsteam. Downstream you’d want source. Ideally, you’d just do source-dest on both…

  10. oval
    November 7th, 2017

    Q6 – I’m having trouble in identifying which side should I consider as source or destination. If we consider to be on the servers side, shouldn’t it be answer A. Source MAC?

  11. Hank
    November 15th, 2017

    Q6:
    The correct answer is B: src and dest MAC address. It needs to be both in order to handle traffic for both directions. If you choose only MAC or IP, it only works for 1 direction.

    *The SRC address is the bottom switch, and the Dest address is the upper switch going from the PC. Then, they are reversed when coming from the servers. The question is only concerned with the Etherchannel link. Not the PC or the servers.

  12. Jack
    November 26th, 2017

    Question 9:
    After LACP is enabled, you configure each link or the entire channel as active or passive.
    When you run port channels with no associated protocol, the port-channel mode is always on.
    The default port-channel mode is on.

    hence the Answer is On.

  13. ciptech
    December 5th, 2017

    “passive – Enables LACP only when an LACP device is detected. This is the default state.”

    https://www.cisco.com/c/en/us/td/docs/optical/cpt/r9_3/command/reference/cpt93_cr/cpt93_cr_chapter_01000.html

    @bigM & @Jack that is for NX-OS which is used on equipment suitable for Data Center not enterprise network.

  14. Addie
    December 5th, 2017

    Still doubts on Q6

  15. RA
    December 7th, 2017

    Note: By default, when an LACP channel is configured, the LACP channel mode is passive.

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