where does lxc ubuntu 18.04 keep network info


Well-Known Member
Jun 10, 2017
I just saw that Ubuntu 18.04 started using another system for managing its network, i.e netplan. I've created a new Ubuntu 18.04 lxc container, I've assigned an ip, I can see it using "ip address show" command, but I can't understand where this information is kept. In /etc/network/interfaces there's obviously nothing, as ifupdown package doesn't exist anymore, but I can't find anything in /etc/netplan, either. So how does proxmox actually assign the ip and keeps the information consistent throughout reboots?

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So the point was to use the same network implementation for all main distros that use systemd, instead of using the particular solutions that individual distros come with - such as netplan - if I understand correctly.
netplan is just a unified frontend/config format for systemd-networkd and NetworkManager. we already have support for systemd-networkd, so it makes sense to just re-use instead of adding support for netplan.
fits the theme...

on Ubuntu 18.04 LXC you set the networkconfig in proxmox for ipv6 to DHCP and SLAAC. If i use SLAAC i get an error in the container:
● systemd-networkd.service - Network Service
Jun 15 22:25:49 test111 systemd-networkd[46]: /etc/systemd/network/eth0.network:6: Address is invalid, ignoring assignment: auto
So if i set it to DHCP the message is gone. Both configuration seems to be working. But strange, i have no IPV6DHCP Server running. And nevertheless i get also with the DHCP flag an IPV6 from my router.

So what is right? Is something to do on PVE side? Or is there only an dhcpflag on the systemd?

Thanks :)
Hi guys
I have an Ubuntu 18.10 container using systemd-networkd , how I can add this route? :
ip route add via

I tried modifying the systemd network config file located in :
but it does not work.
regards and thanks in advance


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