Hello together,
I’m unexperienced with LXC and IPv6 networking too. As I upgraded my system from Ubuntu 16.04 to 20.04 and from LXC 2.x to LXC 4.x I discovered, that the containers received an IPv4 as before, but no IPv6 as possoble with LXC 4.x:
root@host:~$ lxc-ls -f
NAME STATE AUTOSTART GROUPS IPV4 IPV6 UNPRIVILEGED
C1 RUNNING 1 - 10.0.3.141 - true
C2 RUNNING 1 - 10.0.3.142, 172.17.0.1 - true
C3 RUNNING 1 - 10.0.3.81 - true
[...]
My /etc/default/lxc-net looks this way:
USE_LXC_BRIDGE="true"
LXC_BRIDGE="lxcbr0"
LXC_ADDR="10.0.3.1"
LXC_NETMASK="255.255.255.0"
LXC_NETWORK="10.0.3.0/24"
LXC_DHCP_RANGE="10.0.3.2,10.0.3.254"
LXC_DHCP_MAX="253"
LXC_IPV6_ADDR="fe80::216:3eff:fe00:1"
LXC_IPV6_MASK="64"
LXC_IPV6_NETWORK="fe80::1"
LXC_IPV6_NAT="true"
#LXC_DHCP_CONFILE=/etc/lxc/dnsmasq.conf
#LXC_DOMAIN="lxc"
and container-configs contain network settings this:
# Network configuration
lxc.net.0.type = veth
lxc.net.0.link = lxcbr0
lxc.net.0.flags = up
lxc.net.0.hwaddr = 00:16:3e:04:be:05
In C1 I also see an IPv6 on eth0:
root@C1:/# ifconfig eth0
eth0 Link encap:Ethernet HWaddr 00:16:3e:ab:2a:6f
inet addr:10.0.3.141 Bcast:10.0.3.255 Mask:255.255.255.0
inet6 addr: fe80::216:3eff:feab:2a6f/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:15727 errors:0 dropped:0 overruns:0 frame:0
TX packets:18848 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:8003917 (8.0 MB) TX bytes:5562112 (5.5 MB)
Do I have to make certain changes in sysctl or network settings to enable IPv6 for LXC?
I very much appreciate your help! If you need any more info, please let me know.