Simple bridge not working (because of docker?)

Ubuntu 16.04.3 Server (HW enabled)

I have used a simple bridge for LXC for years. It looks like this: /etc/network/interfaces

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

    source /etc/network/interfaces.d/*

    # The loopback network interface
    auto lo
    iface lo inet loopback

    # The primary network interface
    auto eno1
    iface eno1 inet manual

    # Bridge
    auto br0
    iface br0 inet dhcp
    	bridge-ifaces eno1
    	bridge-ports eno1
    	up ifconfig eno1 up

Here’s a conf example from a container:

lxc.include = /usr/share/lxc/config/ubuntu.common.conf
lxc.start.auto = 1
lxc.rootfs = /var/lib/lxc/kids/rootfs
lxc.rootfs.backend = dir
lxc.utsname = kids
lxc.arch = amd64
lxc.network.type = veth
lxc.network.link = br0
lxc.network.flags = up
lxc.network.hwaddr = 00:16:3e:db:83:e9

lxc.mount.entry = /mnt/Multimedia  /var/lib/lxc/kids/rootfs/media/Multimedia none bind 0 0

I have sevral dockers running on the same server and here is an output of the network:

anders@harbor:~$ ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host 
       valid_lft forever preferred_lft forever
2: eno1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master br0 state UP group default qlen 1000
    link/ether 90:b1:1c:9d:ed:9d brd ff:ff:ff:ff:ff:ff
    inet6 fe80::92b1:1cff:fe9d:ed9d/64 scope link 
       valid_lft forever preferred_lft forever
3: enp2s0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 68:05:ca:2a:39:82 brd ff:ff:ff:ff:ff:ff
4: br0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 90:b1:1c:9d:ed:9d brd ff:ff:ff:ff:ff:ff
    inet 10.0.1.200/24 brd 10.0.1.255 scope global br0
       valid_lft forever preferred_lft forever
    inet6 fe80::92b1:1cff:fe9d:ed9d/64 scope link 
       valid_lft forever preferred_lft forever
6: vethD5VXQV@if5: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master br0 state UP group default qlen 1000
    link/ether fe:a8:c7:40:c9:f1 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet6 fe80::fca8:c7ff:fe40:c9f1/64 scope link 
       valid_lft forever preferred_lft forever
7: docker0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default 
    link/ether 02:42:eb:83:06:a2 brd ff:ff:ff:ff:ff:ff
    inet 172.17.0.1/16 scope global docker0
       valid_lft forever preferred_lft forever
    inet6 fe80::42:ebff:fe83:6a2/64 scope link 
       valid_lft forever preferred_lft forever
9: vetha76239d@if8: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP group default 
    link/ether 12:91:01:95:29:2a brd ff:ff:ff:ff:ff:ff link-netnsid 1
    inet6 fe80::1091:1ff:fe95:292a/64 scope link 
       valid_lft forever preferred_lft forever
11: vethbaa7858@if10: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP group default 
    link/ether 7e:7a:cf:fb:ec:bb brd ff:ff:ff:ff:ff:ff link-netnsid 2
    inet6 fe80::7c7a:cfff:fefb:ecbb/64 scope link 
       valid_lft forever preferred_lft forever
13: veth85b3057@if12: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP group default 
    link/ether 6a:44:c4:14:e7:d4 brd ff:ff:ff:ff:ff:ff link-netnsid 3
    inet6 fe80::6844:c4ff:fe14:e7d4/64 scope link 
       valid_lft forever preferred_lft forever
15: veth6cbc09e@if14: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP group default 
    link/ether 72:8f:df:a7:bf:69 brd ff:ff:ff:ff:ff:ff link-netnsid 4
    inet6 fe80::708f:dfff:fea7:bf69/64 scope link 
       valid_lft forever preferred_lft forever
17: veth1aa75d5@if16: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP group default 
    link/ether 9a:c2:02:4d:cb:19 brd ff:ff:ff:ff:ff:ff link-netnsid 5
    inet6 fe80::98c2:2ff:fe4d:cb19/64 scope link 
       valid_lft forever preferred_lft forever
19: vethf785a0c@if18: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master docker0 state UP group default 
    link/ether aa:13:5a:69:52:7f brd ff:ff:ff:ff:ff:ff link-netnsid 6
    inet6 fe80::a813:5aff:fe69:527f/64 scope link 
       valid_lft forever preferred_lft forever

Now I use DHCP reserve to mac to give my server the same adress every time. But now this bridge does not work with LXC any more. The only difference on this server is that I have Docker installed and running. Is there any known issues combining docker and LXC like this?

Container /etc/network/interfaces

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

# The loopback network interface
auto lo
iface lo inet loopback

auto eth0
iface eth0 inet dhcp

Container debug:

lxc-start 20171026115614.869 INFO     lxc_start_ui - tools/lxc_start.c:main:275 - using rcfile /var/lib/lxc/kids/config
      lxc-start 20171026115614.869 WARN     lxc_confile - confile.c:config_pivotdir:1916 - lxc.pivotdir is ignored.  It will soon become an error.
      lxc-start 20171026115614.870 DEBUG    lxc_monitor - monitor.c:lxc_monitord_spawn:330 - Going to wait for pid 12560.
      lxc-start 20171026115614.871 DEBUG    lxc_monitor - monitor.c:lxc_monitord_spawn:349 - Trying to sync with child process.
      lxc-start 20171026115614.871 INFO     lxc_start - start.c:lxc_check_inherited:235 - Closed inherited fd: 3.
      lxc-start 20171026115614.871 INFO     lxc_start - start.c:lxc_check_inherited:235 - Closed inherited fd: 5.
      lxc-start 20171026115614.871 DEBUG    lxc_monitor - monitor.c:lxc_monitord_spawn:387 - Using pipe file descriptor 6 for monitord.
      lxc-start 20171026115614.876 DEBUG    lxc_monitor - monitor.c:lxc_monitord_spawn:364 - Successfully synced with child process.
      lxc-start 20171026115614.876 DEBUG    lxc_monitor - monitor.c:lxc_monitord_spawn:333 - Finished waiting on pid 12560.
      lxc-start 20171026115614.877 INFO     lxc_container - lxccontainer.c:do_lxcapi_start:802 - Attempting to set proc title to [lxc monitor] /var/lib/lxc kids
      lxc-start 20171026115614.877 INFO     lxc_start - start.c:lxc_check_inherited:235 - Closed inherited fd: 3.
      lxc-start 20171026115614.877 INFO     lxc_lsm - lsm/lsm.c:lsm_init:48 - LSM security driver AppArmor
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:parse_config_v2:418 - processing: .reject_force_umount  # comment this to allow umount -f;  not recommended.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:parse_config_v2:590 - Adding native rule for reject_force_umount action 0.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:do_resolve_add_rule:259 - Setting Seccomp rule to reject force umounts.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:parse_config_v2:593 - Adding compat rule for reject_force_umount action 0.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:do_resolve_add_rule:259 - Setting Seccomp rule to reject force umounts.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:do_resolve_add_rule:259 - Setting Seccomp rule to reject force umounts.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:parse_config_v2:418 - processing: .[all].
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:parse_config_v2:418 - processing: .kexec_load errno 1.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:parse_config_v2:590 - Adding native rule for kexec_load action 327681.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:parse_config_v2:593 - Adding compat rule for kexec_load action 327681.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:parse_config_v2:418 - processing: .open_by_handle_at errno 1.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:parse_config_v2:590 - Adding native rule for open_by_handle_at action 327681.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:parse_config_v2:593 - Adding compat rule for open_by_handle_at action 327681.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:parse_config_v2:418 - processing: .init_module errno 1.
      lxc-start 20171026115614.877 DEBUG    lxc_monitor - monitor.c:lxc_monitord_spawn:330 - Going to wait for pid 12564.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:parse_config_v2:590 - Adding native rule for init_module action 327681.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:parse_config_v2:593 - Adding compat rule for init_module action 327681.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:parse_config_v2:418 - processing: .finit_module errno 1.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:parse_config_v2:590 - Adding native rule for finit_module action 327681.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:parse_config_v2:593 - Adding compat rule for finit_module action 327681.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:parse_config_v2:418 - processing: .delete_module errno 1.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:parse_config_v2:590 - Adding native rule for delete_module action 327681.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:parse_config_v2:593 - Adding compat rule for delete_module action 327681.
      lxc-start 20171026115614.877 INFO     lxc_seccomp - seccomp.c:parse_config_v2:603 - Merging in the compat Seccomp ctx into the main one.
      lxc-start 20171026115614.877 DEBUG    lxc_start - start.c:setup_signal_fd:273 - Set SIGCHLD handler with file descriptor: 5.
      lxc-start 20171026115614.878 DEBUG    lxc_monitor - monitor.c:lxc_monitord_spawn:349 - Trying to sync with child process.
      lxc-start 20171026115614.878 INFO     lxc_start - start.c:lxc_check_inherited:235 - Closed inherited fd: 3.
      lxc-start 20171026115614.878 INFO     lxc_start - start.c:lxc_check_inherited:235 - Closed inherited fd: 5.
      lxc-start 20171026115614.878 DEBUG    lxc_monitor - monitor.c:lxc_monitord_spawn:387 - Using pipe file descriptor 6 for monitord.
      lxc-start 20171026115614.878 DEBUG    console - console.c:lxc_console_peer_default:438 - process does not have a controlling terminal
      lxc-start 20171026115614.878 INFO     lxc_start - start.c:lxc_init:475 - Container "kids" is initialized.
      lxc-start 20171026115614.878 DEBUG    lxc_start - start.c:__lxc_start:1329 - Not dropping CAP_SYS_BOOT or watching utmp.
      lxc-start 20171026115614.880 INFO     lxc_conf - conf.c:instantiate_veth:2714 - Retrieved mtu 1500 from br0
      lxc-start 20171026115614.880 INFO     lxc_conf - conf.c:instantiate_veth:2739 - Attached 'vethTUON3B': to the bridge 'br0': 
      lxc-start 20171026115614.880 DEBUG    lxc_conf - conf.c:instantiate_veth:2756 - instantiated veth 'vethTUON3B/vethUY2FKC', index is '20'
      lxc-start 20171026115614.880 INFO     lxc_cgroup - cgroups/cgroup.c:cgroup_init:68 - cgroup driver cgroupfs-ng initing for kids
      lxc-start 20171026115614.881 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:filter_and_set_cpus:480 - No isolated cpus detected.
      lxc-start 20171026115614.881 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:handle_cpuset_hierarchy:650 - "cgroup.clone_children" was already set to "1".
      lxc-start 20171026115614.883 INFO     lxc_start - start.c:lxc_spawn:1169 - Cloned CLONE_NEWNS.
      lxc-start 20171026115614.883 INFO     lxc_start - start.c:lxc_spawn:1169 - Cloned CLONE_NEWPID.
      lxc-start 20171026115614.883 INFO     lxc_start - start.c:lxc_spawn:1169 - Cloned CLONE_NEWUTS.
      lxc-start 20171026115614.883 INFO     lxc_start - start.c:lxc_spawn:1169 - Cloned CLONE_NEWIPC.
      lxc-start 20171026115614.883 INFO     lxc_start - start.c:lxc_spawn:1169 - Cloned CLONE_NEWNET.
      lxc-start 20171026115614.883 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.deny' set to 'a'
      lxc-start 20171026115614.883 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c *:* m'
      lxc-start 20171026115614.883 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'b *:* m'
      lxc-start 20171026115614.883 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 1:3 rwm'
      lxc-start 20171026115614.883 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 1:5 rwm'
      lxc-start 20171026115614.883 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 1:7 rwm'
      lxc-start 20171026115614.883 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 5:0 rwm'
      lxc-start 20171026115614.883 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 5:1 rwm'
      lxc-start 20171026115614.883 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 5:2 rwm'
      lxc-start 20171026115614.883 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 1:8 rwm'
      lxc-start 20171026115614.883 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 1:9 rwm'
      lxc-start 20171026115614.883 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 136:* rwm'
      lxc-start 20171026115614.883 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 10:229 rwm'
      lxc-start 20171026115614.883 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 254:0 rm'
      lxc-start 20171026115614.883 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 10:200 rwm'
      lxc-start 20171026115614.883 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 10:228 rwm'
      lxc-start 20171026115614.883 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 10:232 rwm'
      lxc-start 20171026115614.883 INFO     lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1980 - cgroup has been setup
      lxc-start 20171026115614.883 DEBUG    lxc_monitor - monitor.c:lxc_monitord_spawn:364 - Successfully synced with child process.
      lxc-start 20171026115614.884 DEBUG    lxc_monitor - monitor.c:lxc_monitord_spawn:333 - Finished waiting on pid 12564.
      lxc-start 20171026115614.884 INFO     lxc_monitor - monitor.c:lxc_monitor_sock_name:201 - using monitor socket name "lxc/ad055575fe28ddd5//var/lib/lxc" (length of socket name 33 must be <= 105)
      lxc-start 20171026115614.884 DEBUG    lxc_monitor - monitor.c:lxc_monitor_open:225 - opening monitor socket lxc/ad055575fe28ddd5//var/lib/lxc with len 33
      lxc-start 20171026115614.916 DEBUG    lxc_conf - conf.c:lxc_assign_network:3263 - move 'vethUY2FKC'/'(null)' to '12574': .
      lxc-start 20171026115614.917 DEBUG    lxc_conf - conf.c:setup_rootfs:1212 - Mounted rootfs "/var/lib/lxc/kids/rootfs" onto "/usr/lib/x86_64-linux-gnu/lxc" with options "(null)".
      lxc-start 20171026115614.917 INFO     lxc_conf - conf.c:setup_utsname:833 - 'kids' hostname has been setup
      lxc-start 20171026115614.940 DEBUG    lxc_conf - conf.c:setup_hw_addr:2292 - mac address '00:16:3e:db:83:e9' on 'eth0' has been setup
      lxc-start 20171026115614.940 DEBUG    lxc_conf - conf.c:setup_netdev:2519 - 'eth0' has been setup
      lxc-start 20171026115614.940 INFO     lxc_conf - conf.c:setup_network:2540 - network has been setup
      lxc-start 20171026115614.940 INFO     lxc_conf - conf.c:mount_autodev:1062 - Mounting container /dev
      lxc-start 20171026115614.940 INFO     lxc_conf - conf.c:mount_autodev:1085 - Mounted tmpfs onto /usr/lib/x86_64-linux-gnu/lxc/dev
      lxc-start 20171026115614.940 INFO     lxc_conf - conf.c:mount_autodev:1103 - Mounted container /dev
      lxc-start 20171026115614.940 DEBUG    lxc_conf - conf.c:mount_entry:1782 - remounting /sys/fs/fuse/connections on /usr/lib/x86_64-linux-gnu/lxc/sys/fs/fuse/connections to respect bind or remount options
      lxc-start 20171026115614.940 DEBUG    lxc_conf - conf.c:mount_entry:1797 - (at remount) flags for /sys/fs/fuse/connections was 4096, required extra flags are 0
      lxc-start 20171026115614.940 DEBUG    lxc_conf - conf.c:mount_entry:1806 - mountflags already was 4096, skipping remount
      lxc-start 20171026115614.940 DEBUG    lxc_conf - conf.c:mount_entry:1832 - mounted '/sys/fs/fuse/connections' on '/usr/lib/x86_64-linux-gnu/lxc/sys/fs/fuse/connections', type 'none'
      lxc-start 20171026115614.940 DEBUG    lxc_conf - conf.c:mount_entry:1782 - remounting /sys/kernel/debug on /usr/lib/x86_64-linux-gnu/lxc/sys/kernel/debug to respect bind or remount options
      lxc-start 20171026115614.940 DEBUG    lxc_conf - conf.c:mount_entry:1797 - (at remount) flags for /sys/kernel/debug was 4096, required extra flags are 0
      lxc-start 20171026115614.940 DEBUG    lxc_conf - conf.c:mount_entry:1806 - mountflags already was 4096, skipping remount
      lxc-start 20171026115614.940 DEBUG    lxc_conf - conf.c:mount_entry:1832 - mounted '/sys/kernel/debug' on '/usr/lib/x86_64-linux-gnu/lxc/sys/kernel/debug', type 'none'
      lxc-start 20171026115614.940 DEBUG    lxc_conf - conf.c:mount_entry:1782 - remounting /sys/kernel/security on /usr/lib/x86_64-linux-gnu/lxc/sys/kernel/security to respect bind or remount options
      lxc-start 20171026115614.940 DEBUG    lxc_conf - conf.c:mount_entry:1797 - (at remount) flags for /sys/kernel/security was 4110, required extra flags are 14
      lxc-start 20171026115614.941 DEBUG    lxc_conf - conf.c:mount_entry:1832 - mounted '/sys/kernel/security' on '/usr/lib/x86_64-linux-gnu/lxc/sys/kernel/security', type 'none'
      lxc-start 20171026115614.941 DEBUG    lxc_conf - conf.c:mount_entry:1782 - remounting /sys/fs/pstore on /usr/lib/x86_64-linux-gnu/lxc/sys/fs/pstore to respect bind or remount options
      lxc-start 20171026115614.941 DEBUG    lxc_conf - conf.c:mount_entry:1797 - (at remount) flags for /sys/fs/pstore was 4110, required extra flags are 14
      lxc-start 20171026115614.941 DEBUG    lxc_conf - conf.c:mount_entry:1832 - mounted '/sys/fs/pstore' on '/usr/lib/x86_64-linux-gnu/lxc/sys/fs/pstore', type 'none'
      lxc-start 20171026115614.941 DEBUG    lxc_conf - conf.c:mount_entry:1832 - mounted 'mqueue' on '/usr/lib/x86_64-linux-gnu/lxc/dev/mqueue', type 'mqueue'
      lxc-start 20171026115614.941 DEBUG    lxc_conf - conf.c:mount_entry:1782 - remounting /mnt/Multimedia on /usr/lib/x86_64-linux-gnu/lxc//media/Multimedia to respect bind or remount options
      lxc-start 20171026115614.941 DEBUG    lxc_conf - conf.c:mount_entry:1797 - (at remount) flags for /mnt/Multimedia was 4096, required extra flags are 0
      lxc-start 20171026115614.941 DEBUG    lxc_conf - conf.c:mount_entry:1806 - mountflags already was 4096, skipping remount
      lxc-start 20171026115614.941 DEBUG    lxc_conf - conf.c:mount_entry:1832 - mounted '/mnt/Multimedia' on '/usr/lib/x86_64-linux-gnu/lxc//media/Multimedia', type 'none'
      lxc-start 20171026115614.941 INFO     lxc_conf - conf.c:mount_file_entries:2052 - mount points have been setup
      lxc-start 20171026115614.941 INFO     lxc_conf - conf.c:run_script_argv:435 - Executing script "/usr/share/lxcfs/lxc.mount.hook" for container "kids", config section "lxc".
      lxc-start 20171026115614.960 INFO     lxc_conf - conf.c:lxc_fill_autodev:1140 - populating container /dev
      lxc-start 20171026115614.960 DEBUG    lxc_conf - conf.c:lxc_fill_autodev:1177 - created device node "/usr/lib/x86_64-linux-gnu/lxc/dev/null"
      lxc-start 20171026115614.960 DEBUG    lxc_conf - conf.c:lxc_fill_autodev:1177 - created device node "/usr/lib/x86_64-linux-gnu/lxc/dev/zero"
      lxc-start 20171026115614.960 DEBUG    lxc_conf - conf.c:lxc_fill_autodev:1177 - created device node "/usr/lib/x86_64-linux-gnu/lxc/dev/full"
      lxc-start 20171026115614.960 DEBUG    lxc_conf - conf.c:lxc_fill_autodev:1177 - created device node "/usr/lib/x86_64-linux-gnu/lxc/dev/urandom"
      lxc-start 20171026115614.960 DEBUG    lxc_conf - conf.c:lxc_fill_autodev:1177 - created device node "/usr/lib/x86_64-linux-gnu/lxc/dev/random"
      lxc-start 20171026115614.960 DEBUG    lxc_conf - conf.c:lxc_fill_autodev:1177 - created device node "/usr/lib/x86_64-linux-gnu/lxc/dev/tty"
      lxc-start 20171026115614.960 INFO     lxc_conf - conf.c:lxc_fill_autodev:1182 - populated container /dev
      lxc-start 20171026115614.960 DEBUG    lxc_conf - conf.c:lxc_setup_ttydir_console:1522 - created directory for console and tty devices at /usr/lib/x86_64-linux-gnu/lxc/dev/lxc"
      lxc-start 20171026115614.960 DEBUG    lxc_conf - conf.c:lxc_setup_ttydir_console:1608 - mounted "/dev/pts/2" onto "/usr/lib/x86_64-linux-gnu/lxc/dev/lxc/console"
      lxc-start 20171026115614.960 DEBUG    lxc_conf - conf.c:lxc_setup_ttydir_console:1628 - console has been setup under "lxc/console" and symlinked to "/usr/lib/x86_64-linux-gnu/lxc/dev/console"
      lxc-start 20171026115614.960 INFO     lxc_utils - utils.c:lxc_mount_proc_if_needed:1774 - I am 1, /proc/self points to "1"
      lxc-start 20171026115614.975 DEBUG    lxc_conf - conf.c:setup_rootfs_pivot_root:1040 - pivot_root syscall to '/usr/lib/x86_64-linux-gnu/lxc' successful
      lxc-start 20171026115614.976 DEBUG    lxc_conf - conf.c:setup_pivot_root:1342 - finished pivot root
      lxc-start 20171026115614.976 DEBUG    lxc_conf - conf.c:lxc_setup_devpts:1400 - created dummy "/dev/ptmx" file as bind mount target
      lxc-start 20171026115614.976 DEBUG    lxc_conf - conf.c:lxc_setup_devpts:1405 - bind mounted "/dev/pts/ptmx" to "/dev/ptmx"
      lxc-start 20171026115614.976 DEBUG    lxc_conf - conf.c:lxc_create_tty:3577 - allocated pty '/dev/pts/0' (9/12)
      lxc-start 20171026115614.976 DEBUG    lxc_conf - conf.c:lxc_create_tty:3577 - allocated pty '/dev/pts/1' (13/14)
      lxc-start 20171026115614.976 DEBUG    lxc_conf - conf.c:lxc_create_tty:3577 - allocated pty '/dev/pts/2' (15/16)
      lxc-start 20171026115614.976 DEBUG    lxc_conf - conf.c:lxc_create_tty:3577 - allocated pty '/dev/pts/3' (17/18)
      lxc-start 20171026115614.976 INFO     lxc_conf - conf.c:lxc_create_tty:3588 - tty's configured
      lxc-start 20171026115614.976 INFO     lxc_conf - conf.c:setup_tty:985 - 4 tty(s) has been setup
      lxc-start 20171026115614.976 INFO     lxc_conf - conf.c:setup_personality:1441 - set personality to '0x0'
      lxc-start 20171026115614.976 DEBUG    lxc_conf - conf.c:setup_caps:2202 - drop capability 'mac_admin' (33)
      lxc-start 20171026115614.976 DEBUG    lxc_conf - conf.c:setup_caps:2202 - drop capability 'mac_override' (32)
      lxc-start 20171026115614.976 DEBUG    lxc_conf - conf.c:setup_caps:2202 - drop capability 'sys_time' (25)
      lxc-start 20171026115614.976 DEBUG    lxc_conf - conf.c:setup_caps:2202 - drop capability 'sys_module' (16)
      lxc-start 20171026115614.976 DEBUG    lxc_conf - conf.c:setup_caps:2202 - drop capability 'sys_rawio' (17)
      lxc-start 20171026115614.976 DEBUG    lxc_conf - conf.c:setup_caps:2211 - capabilities have been setup
      lxc-start 20171026115614.976 NOTICE   lxc_conf - conf.c:lxc_setup:4124 - 'kids' is setup.
      lxc-start 20171026115614.976 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.deny' set to 'a'
      lxc-start 20171026115614.976 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c *:* m'
      lxc-start 20171026115614.976 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'b *:* m'
      lxc-start 20171026115614.976 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 1:3 rwm'
      lxc-start 20171026115614.976 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 1:5 rwm'
      lxc-start 20171026115614.976 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 1:7 rwm'
      lxc-start 20171026115614.976 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 5:0 rwm'
      lxc-start 20171026115614.976 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 5:1 rwm'
      lxc-start 20171026115614.976 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 5:2 rwm'
      lxc-start 20171026115614.976 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 1:8 rwm'
      lxc-start 20171026115614.976 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 1:9 rwm'
      lxc-start 20171026115614.976 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 136:* rwm'
      lxc-start 20171026115614.976 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 10:229 rwm'
      lxc-start 20171026115614.976 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 254:0 rm'
      lxc-start 20171026115614.976 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 10:200 rwm'
      lxc-start 20171026115614.976 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 10:228 rwm'
      lxc-start 20171026115614.976 DEBUG    lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1976 - cgroup 'devices.allow' set to 'c 10:232 rwm'
      lxc-start 20171026115614.976 INFO     lxc_cgfsng - cgroups/cgfsng.c:cgfsng_setup_limits:1980 - cgroup has been setup
      lxc-start 20171026115614.976 INFO     lxc_start - start.c:do_start:836 - Unshared CLONE_NEWCGROUP.
      lxc-start 20171026115614.976 INFO     lxc_apparmor - lsm/apparmor.c:apparmor_process_label_set:238 - changed apparmor profile to lxc-container-default-cgns
      lxc-start 20171026115614.977 NOTICE   lxc_start - start.c:start:1440 - Exec'ing "/sbin/init".
      lxc-start 20171026115614.977 NOTICE   lxc_start - start.c:post_start:1451 - Started "/sbin/init" with pid "12574".
      lxc-start 20171026115614.977 NOTICE   lxc_start - start.c:signal_handler:322 - Received SIGCHLD from pid 12566 instead of container init 12574.
      lxc-start 20171026115614.977 DEBUG    lxc_commands - commands.c:lxc_cmd_handler:901 - Peer has disconnected.
      lxc-start 20171026115614.977 DEBUG    lxc_commands - commands.c:lxc_cmd_rsp_recv:203 - command get_state response data length is 0
      lxc-start 20171026115614.977 DEBUG    lxc_commands - commands.c:lxc_cmd_get_state:586 - Container "kids" is in "RUNNING" state.
      lxc-start 20171026115614.977 DEBUG    lxc_commands - commands.c:lxc_cmd_handler:901 - Peer has disconnected.
      lxc-start 20171026115624.998 DEBUG    lxc_commands - commands.c:lxc_cmd_handler:901 - Peer has disconnected.
      lxc-start 20171026115624.998 DEBUG    lxc_commands - commands.c:lxc_cmd_handler:901 - Peer has disconnected.
      lxc-start 20171026115624.998 DEBUG    lxc_commands - commands.c:lxc_cmd_handler:901 - Peer has disconnected.
      lxc-start 20171026115624.998 DEBUG    lxc_commands - commands.c:lxc_cmd_handler:901 - Peer has disconnected.
      lxc-start 20171026115624.999 DEBUG    lxc_commands - commands.c:lxc_cmd_handler:901 - Peer has disconnected.
      lxc-start 20171026115624.999 DEBUG    lxc_commands - commands.c:lxc_cmd_handler:901 - Peer has disconnected.
      lxc-start 20171026115625.584 DEBUG    lxc_commands - commands.c:lxc_cmd_handler:901 - Peer has disconnected.
      lxc-start 20171026115625.592 DEBUG    lxc_commands - commands.c:lxc_cmd_handler:901 - Peer has disconnected.
      lxc-start 20171026115625.105 DEBUG    lxc_start - start.c:signal_handler:326 - Container init process 12574 exited.
      lxc-start 20171026115625.105 DEBUG    lxc_start - start.c:__lxc_start:1384 - Container "kids" is halting.
      lxc-start 20171026115625.105 DEBUG    lxc_start - start.c:__lxc_start:1399 - Pushing physical nics back to host namespace
      lxc-start 20171026115625.106 DEBUG    lxc_start - start.c:__lxc_start:1402 - Tearing down virtual network devices used by container "kids".
      lxc-start 20171026115625.106 INFO     lxc_conf - conf.c:lxc_delete_network:3072 - Interface "(null)" with index 20 already deleted or existing in different network namespace.
      lxc-start 20171026115625.151 INFO     lxc_conf - conf.c:lxc_delete_network:3105 - Removed interface "vethTUON3B" from host.
      lxc-start 20171026115625.152 INFO     lxc_error - error.c:lxc_error_set_and_log:54 - Child <12574> ended on signal (2).
      lxc-start 20171026115625.184 INFO     lxc_conf - conf.c:run_script_argv:435 - Executing script "/usr/share/lxcfs/lxc.reboot.hook" for container "kids", config section "lxc".

Solved it.

sudo nano /etc/sysctl.conf

Uncomment:

net.ipv4.ip_forward=1

I cant remember ever having to do that before.

cleaned up /etc/network/interfaces as well.

# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).

source /etc/network/interfaces.d/*

# The loopback network interface
auto lo
iface lo inet loopback

    # Bridge

    auto br0
    iface br0 inet dhcp
    	bridge-ifaces eno1
    	bridge-ports eno1
    	up ifconfig eno1 up
    iface eno1 inet manual

Not sure what did the trick… (or maybe just my router was not feeling well).