How to create container with two network interface

LXD
,
3

Sorry this is first time i use LXC/LXD, in case of switching from docker, so i still confused the difference, so let me tell about my last try, after i read this thread Add multiple nic to lxc containers

First time i’m trying to use this configuration

lxc network create external ipv6.address=none ipv4.address=10.20.20.1/24 ipv4.nat=true
lxc network create internal ipv6.address=none ipv4.address=10.10.10.1/24 ipv4.nat=false

lxc launch ubuntu:20.04 server
lxc launch ubuntu:20.04 client

lxc config device add server eth0 nic name=eth0 nictype=bridged parent=external ipv4.address=10.20.20.10
lxc config device add server eth1 nic name=eth1 nictype=bridged parent=internal ipv4.address=10.10.10.10

lxc config device add client eth0 nic name=eth0 nictype=bridged parent=internal ipv4.address=10.10.10.11

when i test the connection, i can ping both from client to server or server to client

then i change my configuration to this

lxc network create external ipv6.address=none ipv4.address=10.20.20.1/24 ipv4.nat=true
lxc network create internal ipv6.address=none ipv4.address=none ipv4.nat=false

lxc launch ubuntu:20.04 server
lxc launch ubuntu:20.04 client

lxc config device add server eth0 nic name=eth0 nictype=bridged parent=external ipv4.address=10.20.20.10
lxc config device add server eth1 nic name=eth1 nictype=bridged parent=internal ipv4.address=10.10.10.1

lxc config device add client eth0 nic name=eth0 nictype=bridged parent=internal ipv4.address=10.10.10.2

but it fail to communicate each other both server and client, i’m also have setup the netplan manually and execute netplan apply to restart the config and this still not connected