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  • 1.  network for small 2-node vSAN environment

    Posted Sep 28, 2020 10:23 AM

    Hi all,

    I'm new to vSphere and vSAN, and m trying to setup a small 2 node vSAN environment to run several servers. 

    Due to lack of network resources, I'm only given single VLAN.

    Would like to know if it's feasible to put all vmnic (mgmt, vmotion,witness,vSAN) on the same VLAN, using different IP address ranges ?  e.g.



    And also want to experiment nic HA feature by adding active/standby adapter for each VM kernel interface (vmk*).

    Will there be any potential problem or even looping in such network configuration?

    Sorry for the newbie question.

    Thanks a lot.


  • 2.  RE: network for small 2-node vSAN environment
    Best Answer

    Posted Sep 28, 2020 10:38 AM


    You can use the same VLAN for all the traffic types (But again, it is highly recommended to use different vlans for each type)

    If you have multiple pNICs you can use both as ACTIVE and the VM traffic for example will be balanced based on the source (or depending the balancing algorithm you select) and instead of having one active and the other just waiting for a failure. (In the A-A scenario if one NIC fails, all the traffic will be redirect to the secondary one, so its a win win situation)

    ESXi filters all BPDU packets, and each PNIC in the VSwitch work as independent adapters (is not like the regular behavior of a network switch) So for example, you can have your two adapter in an active mode connected to the same physical switch that is not going to be issues. VMware Knowledge Base

    Hope that's helps!



  • 3.  RE: network for small 2-node vSAN environment

    Posted Sep 28, 2020 05:36 PM


    Few things to consider:

    1. With vSAN 2node cluster you can use direct connect - you connect servers back to back with 10g (like Server A NIC1 port1 to Server B NIC1 port2, Server A NIC1 port2 to Server B NIC1 port2). You need configure dedicated switch for this and connect there relevant uplinks. You can use this for VSAN and for vMotion, as these networks usually do not require L3 connectivity.
    AFAIR recommended uplink policy is to configure those uplinks in the dual active - standby -> smthg like VSAN vmk uplink1 Active, uplink2 Standby; vMotion vmk uplink1 Standby, uplink2 Active

    2. Generally you have 3 options for witness network:

    a) in the same network as VSAN

    b) in the same network as ESXi mgmt

    c) in the separate network accessible via ESXi mgmt default gateway

    3. In the direct connect VSAN you can put witness in the same network as the ESXi mgmt. You just need to reconfigure VSAN to use mgmt network for VSAN witness connectivity.

    You just need to host witness outside those 2 nodes.

    Unfortunately I cannot help you more.

    I demoed such config like 1,5 year ago and it worked pretty well.

    Hope that helps

  • 4.  RE: network for small 2-node vSAN environment

    Posted Sep 30, 2020 03:46 AM

    Thanks a lot for your help. 

    Sorry that seems I'm unable to mark multiple replies as correct answer.  Hope it's okay for you.

    Thanks again.

    Best Regards