How To Add VLANs AFTER a HyperFlex Installation

When you installed a HyperFlex Cluster, VLANs are created at the UCS-Manager and vSwitches of the nodes. But what if you just want to add VLANs to your environment ? How can you do that ?

Add VLAN to existing HyperFlex Cluster

Here you see some VLANs at the vSwitches of vCenter.

And here are the created VLANs in UCS Manager.

Let’s go to the Installer and do a Post_install

We just want to add VLANs so we use the parameter –vlan. The other parameters are just to find the HyperFlex Cluster and the UCS Manager.

root@Cisco-HX-Installer-Appliance:~# post_install --cluster-ip --vlan --ucsm-ip
Logging in to controller

HX CVM root password:
Getting ESX hosts from HX cluster...
vCenter URL:
Enter vCenter username (user@domain): administrator@vsphere.local
vCenter Password:
Found datacenter AMSCCC
Found cluster HXAFM5
UCSM Username: admin
UCSM Password:

Now give a Group Name and the VLAN Description will be the same. At the next question give a numeric value for the VLAN ID.

Port Group Name to add (VLAN ID will be appended to the name): EXTRA
VLAN ID: (0-4096) 10
Adding VLAN 10 to FI
Adding VLAN 10 to vm-network-a VNIC template
Could not connect to UCSM. Please create VLAN manually.
Adding EXTRA-10 to
Adding EXTRA-10 to
Adding EXTRA-10 to
Add additional VM network VLANs? (y/n) n

When we answer the questions, we see that the post_install creates the VLANs at the right vSwitches and UCS Manager.

Now you can see that VLAN EXTRA-10 (10) is created in UCS Manager.


And also on the vSwitch EXTRA-10 with VLANTag 10 is created.


It’s very easy !

Here are some other post regarding HyperFlex which are nice to know :


  1. It didn’t work for me with HyperFlex 2.6. Is this a new feature on 3.0?

    I got this error:
    post_install: error: unrecognized arguments: –vlan

    I have version 2.1:
    root@Cisco-HX-Installer-Appliance:~# post_install –version
    post_install 2.1

  2. Hi just tried the command -vlan and –vlan and i get this error (post_install: error: unrecognized arguments: –vlan) I have version post_install 3.0. Any clues?


  3. Hello,

    What is the installer VM is no more present? , what have to be done if we deploy a new installer VM with an already hyperflex up and running ?

    Thank You,

  4. Thank you for your information. We just add two vlans on Hyperflex 3.5. But we also want to know how to delete or modify the vlan information? BTW, can we finish these creating-vlan steps manually on UCSM rather than using HXDP installer?

    • You can only add vlans with the tool. To delete / modify VLANs you should do it via UCS-Manager.
      The create vlans can also be done via UCS-Manager and some prefer the script.

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