Promiscuous bridge for LXC Container?


Mar 23, 2016
Boston, MA
Hey all,

I am trying to run ntopng in an Ubuntu 14.04LTS container on my Proxmosx host.

I set up my switch (Procurve 1810G-24) to mirror both RX and TX of the port connected to my router, to a separate port on the switch.

Then I connected a designated NIC (eth3) on my Proxmox box to that port.

Judging by the very unscientific method of looking at activity leds, it appears as if traffic is indeed being correctly mirrored to the desired port.

Next, I created a new bridge (vmbr3) and added eth3 to this bridge.

After this, I created a new LXC container, where eth0 is connected to the normal network (VMBr0), and eth1 - configured in promiscuous mode - is connected to vmbr3, the dedicated network bridge that only has the one physical interface.

I installed ntopng, which appears to be running properly, yet it is not receiving any of the mirrored packets.

I'm guessing there is something I need to do in order to allow eth3 and vmbr3 on the proxmox host to promiscuously forward everything received on eth3 to the LXC container, but I am not quite sure what that might be.

Can anyone lend me a hand?


My /etc/network/interfaces on the Proxmox host:

~# cat /etc/network/interfaces
# network interface settings; autogenerated
# Please do NOT modify this file directly, unless you know what
# you're doing.
# If you want to manage part of the network configuration manually,
# please utilize the 'source' or 'source-directory' directives to do
# so.
# PVE will preserve these directives, but will NOT its network
# configuration from sourced files, so do not attempt to move any of
# the PVE managed interfaces into external files!

auto lo
iface lo inet loopback

iface eth0 inet manual

iface eth1 inet manual

iface eth2 inet manual

iface eth3 inet manual

iface eth4 inet manual

iface eth5 inet manual

auto bond0
iface bond0 inet manual
    slaves eth0 eth1 eth2
    bond_miimon 100
    bond_mode 802.3ad
    bond_xmit_hash_policy layer2
    bond-lacp-rate 1

auto vmbr0
iface vmbr0 inet static
    bridge_ports bond0
    bridge_stp off
    bridge_fd 0

auto vmbr1
iface vmbr1 inet static
    bridge_ports none
    bridge_stp off
    bridge_fd 0

auto vmbr2
iface vmbr2 inet manual
    bridge_ports eth4 eth5
    bridge_stp off
    bridge_fd 0

auto vmbr3
iface vmbr3 inet manual
    bridge_ports eth3
    bridge_stp off
    bridge_fd 0
My /etc/network/interfaces on my LXC container:

$ cat /etc/network/interfaces
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet static

auto eth1
iface eth1 inet manual
        up ifconfig eth1 promisc up
        down ifconfig eth1 promisc down
  • Like
Reactions: ilakech


New Member
Jul 7, 2018
I am exactly running into the same issue. I do however see ARP and broadcast traffic coming through, but it looks like the 'promisc' part is being dropped before forwarding it to the container.


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