Wired Intelligent Edge

 View Only
last person joined: 9 hours ago 

Bring performance and reliability to your network with the Aruba Core, Aggregation, and Access layer switches. Discuss the latest features and functionality of the ArubaOS-Switch and ArubaOS-CX devices, and find ways to improve security across your network to bring together a mobile first solution.
Expand all | Collapse all

Aruba-CX Switching: How to identify/test which port of a lag is used for a connection

This thread has been viewed 37 times
  • 1.  Aruba-CX Switching: How to identify/test which port of a lag is used for a connection

    Posted Jan 26, 2022 08:24 AM

    Hi Guys,

    does anyone know if it is possible to identify which port of an lag interface is used?

    Or how to test/calculate it?

    On Cisco devices I know it is possible, and you can enter source/destination pair and it shows the resulting hash and link.

    I did noch find anything like this for the Aruba-CX...

    I want to compare if two different destination IPs tooks the same path between source and destination.

    One VM sends many TCP Retransmit / Dup ACK etc, and an other VM on the same host and switch interface (no lag yet) does not.
    I guess it is a software/VM problem, but to be sure I want to check if there is a difference which links are used in the network.

    Thanks and kind regards

    Robert



    ------------------------------
    Robert Großmann
    ------------------------------


  • 2.  RE: Aruba-CX Switching: How to identify/test which port of a lag is used for a connection

    EMPLOYEE
    Posted Jan 27, 2022 08:49 AM
    -1- It depends on platform (ASIC dependent) and there is not CLI command that allows to calculate it in advance.
    -2- In your VM case, the hashing on switch is not involved for any traffic sourced from hypervisor. This is really a matter of how hypervisor LB is configured
    (on VMware case, IP hash based on virtual port or other options). Switch hashing would matter for return traffic. If hypervisor connection is not a lag, then the VM MAC is known behind only one given port, and there will be no load-balancing between server NICs.
    -3- hashing setting on AOS-CX is configurable with L3 hashing or even  L4-hashing tcp/udp srv/dst port.

    ------------------------------
    Vincent Giles
    ------------------------------



  • 3.  RE: Aruba-CX Switching: How to identify/test which port of a lag is used for a connection

    Posted Jan 27, 2022 09:30 AM

    Hi Vincent,

    1. Thats bad, why cant aruba do such simple things?
    2. That was not the question. I was looking for the switch path (between source and destination switch). I know which ports on the edge sites to the server and client are used.
    3. That even was not the question. Of course that is configurable (L2/L3/L4, but not L3+L4). But It does not help to identify which link a specified traffic flow goes.


    That means troubleshooting is very difficult, as I can't say which switch interfaces are traversed by a specific traffic flow.

    And as I cannnot filter mirrrored traffic, mirroring is not an option... 100G Uplink Ports -> 1G Laptop LAN Port...

    Kind regards



    ------------------------------
    Robert Großmann
    ------------------------------



  • 4.  RE: Aruba-CX Switching: How to identify/test which port of a lag is used for a connection

    EMPLOYEE
    Posted Jan 27, 2022 10:05 AM
    I would suggest to raise your dissatisfaction to your local Aruba representative so he can raise this request to the product management group and find a solution for you.
    Best regards,

    ------------------------------
    Vincent Giles
    ------------------------------



  • 5.  RE: Aruba-CX Switching: How to identify/test which port of a lag is used for a connection

    Posted Jan 27, 2022 10:27 AM

    Hi Vincent,

    I apologize if it sounds rough to you, That was not my intend. But the troubles with aruba cx are getting more and more and migration has stopped, and the tac...

    I will contact our dealer and representative, and parallel i opened a new idea in the innovation zone. But the activity and feedback there is.... not worth to mention.

    Have a nice day!

    And if someone does have a idea or a hidden command (cli or shell) to get the needed information, that would be helpful.

    Kind Regards

    Robert



    ------------------------------
    Robert Großmann
    ------------------------------



  • 6.  RE: Aruba-CX Switching: How to identify/test which port of a lag is used for a connection

    MVP GURU
    Posted Jan 27, 2022 10:34 AM
    Hi Robert, currently ArubaOS-CX hasn't this feature (it doesn't mean that a command can't be featured for the task).

    IIRC ArubaOS-Switch (HP ProVision) and HPE Comware both provide commands to understand what physical link of a Links Aggregation logical interface would be used by egressing traffic having very specific characteristics (Source/Destination IPs/Ports)...but not on ArubaOS-CX.

    Note: "L2/L3/L4, but not L3+L4" -> technically speaking when L4 is used if L4 characteristics can't be used to calculate the hashing there is a fallback mechanism to lower level L3, and so on up to L2 from L3.

    ------------------------------
    Davide Poletto
    ------------------------------