What am I doing wrong with this network configuration for KVM (F5 virtual edition)

Hello,

I have been trying to setup an F5 lab using KVM on debian. I currently have the following network configuration (/etc/network/interfaces - see output pasted at end of post)

although whenever I go to create the VM in KVM, only one tap is associated with the bridge (trying to use the taps for management, external, and internal interfaces on the F5 VM). (see screenshot at end of post)

Would anyone have any suggestions for configuring networking properly for this setup? I'm open to anything at this point in time. Thanks for your help.

source /etc/network/interfaces.d/*

auto lo
iface lo inet loopback

allow-hotplug eth0
iface eth0 inet dhcp
iface eth0 inet6 auto

    auto br0
    iface br0 inet dhcp
       pre-up ip tuntap add dev tap0 mode tap user root
       pre-up ip tuntap add dev tap1 mode tap user root
       pre-up ip tuntap add dev tap2 mode tap user root
       pre-up ip link set tap0 up
       pre-up ip link set tap1 up
       pre-up ip link set tap2 up
       bridge_ports all tap0 tap1 tap2
       bridge_stp off
       bridge_maxwait 0
       bridge_fd      0
       post-down ip link set tap0 down
       post-down ip link set tap1 down
       post-down ip link set tap2 down
       post-down ip tuntap del dev tap0 mode tap
       post-down ip tuntap del dev tap1 mode tap
       post-down ip tuntap del dev tap2 mode tap