LXC containers cannot ping outside world

LXD
1

Hello,

After a recent server reboot, my containers are unable to ping the outside world. When I ping, there is no response other than:

root@marmoset03-submit-05:~# ping 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
^C
--- 8.8.8.8 ping statistics ---
5 packets transmitted, 0 received, 100% packet loss, time 3999ms

I have referred to this thread, but not had any luck yet:
https://discuss.linuxcontainers.org/t/lxc-containers-cannot-ping-outside-world-network-is-unreachable/7583

Host OS: Centos 7
Guest OS: Ubuntu 18.04

ip a on the host machine:

[d24lau-adm@marmoset03 ~]$ ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    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 mq state UP group default qlen 1000
    link/ether 0c:c4:7a:ad:1f:b4 brd ff:ff:ff:ff:ff:ff
    inet 129.97.105.45/24 brd 129.97.105.255 scope global noprefixroute eno1
       valid_lft forever preferred_lft forever
    inet6 fe80::ec4:7aff:fead:1fb4/64 scope link noprefixroute
       valid_lft forever preferred_lft forever
3: eno2: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN group default qlen 1000
    link/ether 0c:c4:7a:ad:1f:b5 brd ff:ff:ff:ff:ff:ff
4: eno3: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN group default qlen 1000
    link/ether 0c:c4:7a:ad:1f:b6 brd ff:ff:ff:ff:ff:ff
5: eno4: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc mq state DOWN group default qlen 1000
    link/ether 0c:c4:7a:ad:1f:b7 brd ff:ff:ff:ff:ff:ff
6: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 52:54:00:b2:56:39 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever
7: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc pfifo_fast master virbr0 state DOWN group default qlen 1000
    link/ether 52:54:00:b2:56:39 brd ff:ff:ff:ff:ff:ff
8: lxdbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 00:16:3e:91:04:f3 brd ff:ff:ff:ff:ff:ff
    inet 10.129.221.1/24 scope global lxdbr0
       valid_lft forever preferred_lft forever
    inet6 fd42:a693:78c7:b0b9::1/64 scope global
       valid_lft forever preferred_lft forever
    inet6 fe80::216:3eff:fe62:b0f5/64 scope link
       valid_lft forever preferred_lft forever
10: veth62ba338f@if9: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master lxdbr0 state UP group default qlen 1000
    link/ether 6a:26:8b:4a:b5:ed brd ff:ff:ff:ff:ff:ff link-netnsid 0
20: vethede25ae9@if19: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master lxdbr0 state UP group default qlen 1000
    link/ether da:b0:2f:ed:82:6a brd ff:ff:ff:ff:ff:ff link-netnsid 2
44: vethad343f7c@if43: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue master lxdbr0 state UP group default qlen 1000
    link/ether 1e:8f:f4:6d:18:0e brd ff:ff:ff:ff:ff:ff link-netnsid 1

ip r on the host machine:

[d24lau-adm@marmoset03 ~]$ ip r
default via 129.97.105.1 dev eno1 proto static metric 100
10.129.221.0/24 dev lxdbr0 proto kernel scope link src 10.129.221.1
129.97.105.0/24 dev eno1 proto kernel scope link src 129.97.105.45 metric 100
192.168.122.0/24 dev virbr0 proto kernel scope link src 192.168.122.1

ip a on the guest:

root@marmoset03-submit-05:~# ip a
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    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
43: eth0@if44: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 00:16:3e:32:85:6d brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 10.129.221.213/24 brd 10.129.221.255 scope global dynamic eth0
       valid_lft 2953sec preferred_lft 2953sec
    inet6 fd42:a693:78c7:b0b9:216:3eff:fe32:856d/64 scope global dynamic mngtmpaddr noprefixroute
       valid_lft 3203sec preferred_lft 3203sec
    inet6 fe80::216:3eff:fe32:856d/64 scope link
       valid_lft forever preferred_lft forever

ip r on the guest:

root@marmoset03-submit-05:~# ip r
default via 10.129.221.1 dev eth0 proto dhcp src 10.129.221.213 metric 100
10.129.221.0/24 dev eth0 proto kernel scope link src 10.129.221.213
10.129.221.1 dev eth0 proto dhcp scope link src 10.129.221.213 metric 100

Any assistance would be greatly appreciated.

1 Like
2

I did try adding the following to /etc/dnsmasq.conf:

listen-address=::1,127.0.0.1,129.97.105.45

Then I restarted dnsmasq with sudo systemctl restart dnsmasq and restarted the container, but that didn’t seem to make a difference.

3

Just in case it is helpful, here is the result of sudo netstat -tulnp | grep :53 on the host:

[d24lau-adm@marmoset03 ~]$ sudo netstat -tulnp | grep :53
tcp        0      0 10.129.221.1:53         0.0.0.0:*               LISTEN      13438/dnsmasq
tcp        0      0 192.168.122.1:53        0.0.0.0:*               LISTEN      4125/dnsmasq
tcp6       0      0 fd42:a693:78c7:b0b9::53 :::*                    LISTEN      13438/dnsmasq
tcp6       0      0 fe80::216:3eff:fe62::53 :::*                    LISTEN      13438/dnsmasq
udp        0      0 10.129.221.1:53         0.0.0.0:*                           13438/dnsmasq
udp        0      0 192.168.122.1:53        0.0.0.0:*                           4125/dnsmasq
udp        0      0 0.0.0.0:5353            0.0.0.0:*                           3244/avahi-daemon:
udp6       0      0 fd42:a693:78c7:b0b9::53 :::*                                13438/dnsmasq
udp6       0      0 fe80::216:3eff:fe62::53 :::*                                13438/dnsmasq

And the result of lxc network show lxdbr0:

root@marmoset03-submit-05:~# [d24lau-adm@marmoset03 ~]$ lxc network show lxdbr0
config:
  ipv4.address: 10.129.221.1/24
  ipv4.nat: "true"
  ipv6.address: fd42:a693:78c7:b0b9::1/64
  ipv6.nat: "true"
  volatile.bridge.hwaddr: 00:16:3e:91:04:f3
description: ""
name: lxdbr0
type: bridge
used_by:
- /1.0/instances/marmoset-build-ece-05
- /1.0/instances/marmoset-build-ece-06
- /1.0/instances/marmoset-build-mme-01
- /1.0/instances/marmoset03-submit-01
- /1.0/instances/marmoset03-submit-05
- /1.0/profiles/default
managed: true
status: Created
locations:
- none

Here is lxc config show <container> --expanded

[d24lau-adm@marmoset03 lxd]$ lxc config show marmoset03-submit-05 --expanded
architecture: x86_64
config:
  image.architecture: amd64
  image.description: ubuntu 18.04 LTS amd64 (release) (20191205)
  image.label: release
  image.os: ubuntu
  image.release: bionic
  image.serial: "20191205"
  image.type: squashfs
  image.version: "18.04"
  security.privileged: "true"
  volatile.base_image: f75468c572cc50eca7f76391182e6fdaf58431f84c3d35a2c92e83814e701698
  volatile.eth0.host_name: veth010c66a1
  volatile.eth0.hwaddr: 00:16:3e:32:85:6d
  volatile.idmap.base: "0"
  volatile.idmap.current: '[]'
  volatile.idmap.next: '[]'
  volatile.last_state.idmap: '[]'
  volatile.last_state.power: RUNNING
devices:
  eth0:
    name: eth0
    nictype: bridged
    parent: lxdbr0
    type: nic
  forward_marmoset03_80_http:
    connect: tcp:10.129.221.213:80
    listen: tcp:129.97.105.45:80
    type: proxy
  forward_marmoset03_443_https:
    connect: tcp:10.129.221.213:443
    listen: tcp:129.97.105.45:443
    type: proxy
  forward_marmoset03_8080_tomcat:
    connect: tcp:10.129.221.213:8080
    listen: tcp:129.97.105.45:8080
    type: proxy
  root:
    path: /
    pool: default
    type: disk
ephemeral: false
profiles:
- default
stateful: false
description: ""
4

Restarting lxd with systemctl reload snap.lxd.daemon seems to have fixed the issue.

5

I hit the same issue today. Server (Ubuntu 22.04) reboot after apt upgrade. I have Docker and LXD both installed from Snap. Docker container networking was working but LXD containers could not ping outside world, could only ping each other using IP6 (not IP4).

Solution was:

sudo systemctl reload snap.lxd.daemon
sudo snap restart lxd
6

https://linuxcontainers.org/lxd/docs/master/howto/network_bridge_firewalld/#prevent-issues-with-lxd-and-docker