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  • 1.  Connecting 3810m to 6200m via aggregate fibre links

    Posted Jun 06, 2025 03:58 AM
      |   view attached

    Hi folks, I'm familiar with the 3810m, but new to the 6200m - the fact that the 6200m is very different in the CLI has come as a nasty surprise, especially because I'm putting together a new site that's time-critical.

    We have lots of aggregate links at our various sites that use 3810m stacks, they're really easy. I can't figure out what I'm doing wrong trying to link a 31810m stack to a 6200m stack. In this simplified example I've two VLANs, 11 and 40, that need to traverse the link, and I don't care about the default VLAN.

    Can anyone tell me where I've gone wrong or where I should start with a diagnosis? Any assistance very much appreciated!

    ########## 3810m config ###########
    
    trunk 3/A4,4/A4 trk5 lacp
    
    vlan 1
       name "DEFAULT_VLAN"
       untagged Trk5
       ip address dhcp-bootp
       exit
    
    vlan 11
       name "lan"
       tagged Trk5
       ip address 10.240.75.253 255.255.255.0
       exit
    
    vlan 40
       name "structure"
       tagged Trk5
       ip address 10.240.74.253 255.255.255.128
       exit
    
    ########## 6200m config ###########
    
    vlan 11
       description lan
       exit
    vlan 40
       description structure
       exit
    interface vlan 11
       description lan
       exit
    interface vlan 40
       description structure
       exit
    
    interface lag 1
       description datacentre
       no shutdown
       vlan trunk native 1
       # allow all is lazy, restrict later
       vlan trunk allowed all
       #lacp mode active
       lacp mode passive
       interface 1/1/51
          no shutdown
          lag 1
       interface 2/1/51
          no shutdown
          lag 1
       exit
    
    

    Attachment(s)

    txt
    aruba link 3810m 6200m.txt   888 B 1 version


  • 2.  RE: Connecting 3810m to 6200m via aggregate fibre links

    Posted Jun 06, 2025 04:46 AM

    Hi, why it was set lacp mode passive (and not simply active) on the lag1's on the Aruba CX 6200M VSF stack side?

    AFAIK the VLANs membership look good on both sides (lazy vlan trunk allowed all apart: this could be easily changed into vlan trunk allowed 1,11,40 instead...obtaining the same result).

    It's important to match the trk5's VLANs membership on the Aruba 3810M backplane stack side with the corresponding peer lag1's VLANs membership on the Aruba CX 6200M VSF stack side.

    On the Aruba 3810M backplane stack do perform a basica check with:

    show lacp

    show trunk

    show vlan ports ethernet trk5 detail

    On the Aruba CX 6200M VSF stack do perform a basic check with:

    show vlan 1

    show vlan 11

    show vlan 40

    show interface lag 1

    show lacp aggregates lag1




  • 3.  RE: Connecting 3810m to 6200m via aggregate fibre links

    Posted Jun 06, 2025 06:08 AM

    Hi, and thanks for your response - for LACP I tried both active and passive, to see if either worked, as I wasn't certain which was needed (for the aggregated links on 3810m I've never had to specify and I assume that active is the default and it's ok for both ends to be active). Thanks for the command to aid diagnosis. Currently I'm struggling with the change, though no doubt I'll get used to it eventually! I'm back on site on Sunday - unfortunately this aggregate link is what connects the stack to our WAN infrastructure so I'm unable to work on it remotely.