vmx NIC ordering for pfSense on vSphere 5.5+



  • When adding a 5th VMXNet3 NIC to a pfSense guest running on vSphere 5.5+, the NIC ordering gets mixed up. Example:
    4 vmxnet3 NICs:
    NIC1 = vmx0
    NIC2 = vmx1
    NIC3 = vmx2
    NIC4 = vmx3

    5 vmxnet3 NICs:
    NIC1 = vmx0
    NIC2 = vmx2
    NIC3 = vmx3
    NIC4 = vmx4
    NIC5 = vmx1

    This occurs during initial install as well as if you change the configuration later on. In the latter case, this can really make things complicated because the configuration for a given NIC isn't bound to the MAC address so the configuration on the system slides around and isn't correct after reboot. This can make access not function, especially in the common case where vmx0 is WAN and vmx1 is LAN.


  • Rebel Alliance Developer Netgate

    That's a known issue and has been that way for years. It really doesn't have anything to do with pfSense or VMXNET though, ESX will reorder the NICs after adding the 5th one no matter what the guest OS is running.



  • Yeah that's a fun esx feature



  • One solution to keep NICs to a minimum is to use VLANs instead.
    IE: set your VMNIC on vlan 4095 (all vlans) and then pop them off as needed inside pfSense.