Use uma ponte no host.
O arquivo de configuração do LXC determina qual será o endereçamento IP do guest / containers.
# ifconfig
br0 Link encap:Ethernet HWaddr 22:C7:47:62:9C:02
inet addr:10.2.0.6 Bcast:10.2.127.255 Mask:255.255.128.0
inet6 addr: fe80::e611:5bff:febe:b62a/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1756184372 errors:0 dropped:0 overruns:0 frame:0
TX packets:470262588 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:112684582109 (104.9 GiB) TX bytes:657886062154 (612.7 GiB)
E um exemplo de arquivo de configuração do LXC ...
# cat /etc/lxc/Analytics.conf
lxc.utsname = Analytics
lxc.tty = 4
lxc.network.type = veth
lxc.network.flags = up
lxc.network.link = br0
lxc.network.name = eth0
lxc.network.mtu = 1500
lxc.network.ipv4 = 10.2.0.80/17
lxc.network.hwaddr = 00:30:6E:08:EC:80
lxc.rootfs = /srv/lxc/Analytics
lxc.mount = /etc/lxc/Analytics.fstab
lxc.cgroup.devices.deny = a
# /dev/null and zero
lxc.cgroup.devices.allow = c 1:3 rwm
lxc.cgroup.devices.allow = c 1:5 rwm
# consoles
lxc.cgroup.devices.allow = c 5:1 rwm
lxc.cgroup.devices.allow = c 5:0 rwm
lxc.cgroup.devices.allow = c 4:0 rwm
lxc.cgroup.devices.allow = c 4:1 rwm
# /dev/{,u}random
lxc.cgroup.devices.allow = c 1:9 rwm
lxc.cgroup.devices.allow = c 1:8 rwm
# /dev/pts/*
lxc.cgroup.devices.allow = c 136:* rwm
lxc.cgroup.devices.allow = c 5:2 rwm
# rtc
lxc.cgroup.devices.allow = c 254:0 rwm