Add new interface command - running vm



  • Hello,

    i have following problem. My Setup:

    1 VM with pfSense 2.2.6:

    • Interface WAN = VMX0
    • Interface LAN1 = VM1
    • Interface LAN2 = VM2

    (Its VMware Esxi Environment)

    Now i want to add a additional Interface to this VM - Interface LAN 3 = VMX3. To add this Interface i must restart the VM and after that, pfsense is not available anymore. A Server that is in the same LAN 1 than pfsense can not ping the pfsense and pfsense can not ping the server. It seems that the new interface confusing the other interfaces. When i delete the new interface and restart the vm, all is working again without a problem.

    Is there a command or a option to add/ recognize the new interface in a running environment? Over SSH oder something else?

    Kind regards



  • esx mangles the interface numbers when you add a 4th interface.
    for example vmx1 becomes vmx2 (or the other way around).

    to deal with this, you have to re-assign your interfaces after adding a 4th interface. (do this outside business hours because it'll mean some downtime to get this sorted).

    You could also setup a second virtual-machine and simulate this behaviour (using the config of your production VM) ; once you have found the logic behind it, manually adjust your config.xml and push the changes towards your production VM

    also: you should consider updating to a supported version of pfSense.



  • @heper:

    esx mangles the interface numbers when you add a 4th interface.
    for example vmx1 becomes vmx2 (or the other way around).

    to deal with this, you have to re-assign your interfaces after adding a 4th interface. (do this outside business hours because it'll mean some downtime to get this sorted).

    You could also setup a second virtual-machine and simulate this behaviour (using the config of your production VM) ; once you have found the logic behind it, manually adjust your config.xml and push the changes towards your production VM

    also: you should consider updating to a supported version of pfSense.

    Thank you for your response! I feared i must go that way to assign it after reboot manually.

    I updated to 2.3.2 but then it added the interface after restart and the package installation failed. So my plan is:

    • Interface add
    • Interface assign
    • Backup
    • Update to version 2.3.2


  • yea, its an esx vs freebsd thing, nothing pfSense can do about it. (no clue if it also applies to other OS')



  • So it was exactly like you said. ESX added the 4th Interface at first place. VMX0 -> VMX1 / VMX1 -> VMX2 and so on…

    i had to configure the interfaces manually over Shell and put it into the right order.

    Now everything works fine!


  • Moderator

    If I remember correctly it has something to do with the MAC address VSpehere is assigning the new interface (at random). As most unix/linux sort their interfaces with some kind of "lowest mac address first", there could be the problem in your case. If the random assigned MAC is lower than one of the other 3, it gets mangled.
    (I stand corrected if that's not the case here, but we had a somewhat similar incident with normal BSD and Linux hosts and vSpheres random MAC assignments)

    Greets