I run Docker on Ubuntu server which is working on Odroid (ARM) and never had bigger issues. Recently I had power outage in home and when systemp backup I realised that all my containers stop communicated with external network.
I checked if ip forwarding is turned on and it is. I flushed iptables to allow docker service to reapply setup. Reinstalled docker service as well. Unfortunately nothing helps.
Bridge administrator shows that all is fine (I think):
$ brctl show bridge name bridge id STP enabled interfaces docker0 8000.0242963f101b no vetha51a119
# ip route 172.17.0.0/16 dev docker0 proto kernel scope link src 172.17.0.1
What I discovered is that all start working when I run tcpdump on bridge0 interface which put this interface in promiscuous mode.
Anyone had some similar issues or have a clue how to bite it ?