5 comments

  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

      —
      Hasan

    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.
      thanks,
      Hasan

  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?
    Thanks
    Paul

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