When creating an unprivileged LXC container from an OCI image (e.g. pct create ... --ostype unmanaged) and setting a static IP via:pct set 129 --net0 "name=eth0,bridge=vmbr1,ip=10.0.0.50/24,gw=10.0.0.1"<br>
The Proxmox config (/etc/pve/lxc/129.conf) correctly shows:
net0: name=eth0,bridge=vmbr1,gw=10.0.0.1,ip=10.0.0.50/24,type=veth<br>
However, the generated LXC config (/var/lib/lxc/129/config) only contains:
lxc.net.0.type = veth<br>lxc.net.0.veth.pair = veth129i0<br>lxc.net.0.hwaddr = BC:24:11:63:69:63<br>lxc.net.0.name = eth0<br>lxc.net.0.mtu = 1500<br>lxc.net.0.script.up = /usr/share/lxc/lxcnetaddbr<br>
Missing: lxc.net.0.ipv4.address, lxc.net.0.ipv4.gateway, and lxc.net.0.flags = up.
The veth pair is created and correctly attached to the bridge (via lxcnetaddbr), but inside the container eth0 remains DOWN with no IP assigned:
2: eth0@if34: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc noop state DOWN<br> link/ether bc:24:11:63:69:63 brd ff:ff:ff:ff:ff:ff<br>
Root cause: Proxmox does not set lxc.net.0.ipv4.address in the generated LXC config. Instead, it relies on the container's init system to configure networking by writing /etc/network/interfaces (Alpine/OpenRC) or equivalent files into the container's rootfs before start. For OCI image containers, the rootfs comes from the Docker image, which has no such network init — so the IP is never applied.
Workaround: Manually configure the interface after container start:
pct exec 129 -- ip addr add 10.0.0.50/24 dev eth0
pct exec 129 -- ip link set eth0 up
pct exec 129 -- ip route add default via 10.0.0.1
After this, the container is reachable at 10.0.0.50.
Expected behavior: When ip= is set in net0, Proxmox should generate lxc.net.0.ipv4.address and lxc.net.0.flags = up in the LXC config so the IP is applied at the namespace level, independent of the container's init system.
