1. Dear Hasan,
    I am Jimmy newbie to Dell. I would like to know what is the best practice to do port channel and not to port channel from vlt peer to downstream and from downstream to vlt peer ( is it must have a interconnection in between the pair of switches ? ) Please advise. Thank you

    1. Hi Jimmy,

      you would typically use Static LAGs for VLTi Port Channel (the interconnect between the two VLT peers), with LACP used for port-channels to the downstream servers.
      Here is a list of some of the published best practices for VLT based typologies.

      • Both VLT peers require the same OS10EE version within the production environment, however, a mismatch in version is acceptable during upgrade procedure
      • Backup destination, or heartbeat connectivity, is recommended through the management network
      • Enable spanning tree to avoid unintentional loops in the network
      • Configure identical vlt-mac on both VLT peers to avoid VLT port channel flap during failure scenarios such as VLTi flap and node reboot
      • Increase the delay restore timer in a scaled VLAN configuration
      • Always deploy more than one link for VLTi port channel
      • Implement dynamic LACP for VLT port channels
      • Implement VLT nodes as the root bridge and the backup root bridge
      • Use default active-active VRRP mode in VLT-VLANs
      • Configure symmetrical configurations on VLT port channels and VLT-VLANs on both VLT nodes
      • Identify and correct any mismatches reported by the show vlt mismatch command
      For high-availability, connect VLT port channels to the access nodes. Orphan ports that are connected directly to servers or switches would fail if the connected node goes down


    1. Hi Navneet,
      With the S52xx, the SFP28 or 25G ports, are backward compatible with 10G/1G.
      The QSFP28 or 100G ports, will breakout to 100G, 50G, 40G, 25G or 10G.
      So, the S5296 shoud support 10/1G on the 96x SFP28/25G ports.

  2. Hi Hasan,
    Couple of quick questions on VLT uplinks using OS10 on 2 x S4112T’s
    Firstly is it possible to mix 10G and 100G in a VLT? (I’ve not seen anything to say “Don’t do it!” – but I know historical ether-channel configs did not allow this – but as its not an ether-channel I wondered if this was possible).
    Secondly – if I have an existing 2 x 10G VLT uplink between two switches (because Dell hadnt shipped the 100G cables in time – you can see why question one above now :)) – can I add the 100G uplinks to the existing VLT without downtime and then remove the 2 x 10G config?
    Im happy to hold off if there is a risk of unexpected downtime – just wondered if you have come across this situation before?

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