Help with Docker and CoreOS network bridge

[Matt Rapczynski]

New here to CoreOS and experimenting with Docker containers. Need some networking help.

What I am trying to do is very simple and seems well documented. I want each Docker container to have an IP on the LAN. I followed the steps to set up a simple bridge on the host physical interface. But once the bridge is enabled, the network is no longer accessible to host, i.e cannot ping -c 1 www.google.com, and CoreOS floods the console with the following message.

br0 received packet on eth0 with own address as source address

I am not a networking expert so it's not clear to me how setting up a simple bridge suddenly creates a routing loop.

Below are the network configs in /etc/systemd/network - three simple files. Using CoreOS 647.0 stable deployed from the VMware OVA.

05-br0.netdev (create the bridge)

[NetDev]
Name=br0
Kind=bridge

10-eth0.network (connect physical interface to bridge)

[Match]
Name=eth0

[Network]
Bridge=br0

15-br0.network (give the bridge an address)

[Match]
Name=br0

[Network]
Address=10.201.2.217/24
Gateway=10.201.2.254
DNS=153.18.144.8
DNS=153.18.231.254

Output of brctl

Output of ip route

Output of networkctl

Output of ip addr show

Any ideas? Thanks!

[eugene.y...@coreos.com]

What flags are you passing to docker daemon? I'm assuming you pass "--bridge=br0" but any other ones? Also, is the ping done on the host or in the container?

[Matt Rapczynski]

Correct - I customized docker.service to include -b=br0. When I boot a simple Ubuntu container it looks like it works. The container does get an IP in the right subnet, and I check ip route for correctness which sets the host br0 as the default router.

When I do the ping it does not work in either the container or the host.

[Steve Wilson]

Were you able to find a solution to your networking question?
I'm attempting to setup the same config, and I've hit a wall.